There is a post on 3800 FB group regarding whether it is possible to run a 3800 SC motor with full stack IC without having to chop into the trunk lid

I did purchase a set of custom brackets and mounts for this specific reason in Michigan last year and hoping to do the install this year. Hopefully it works without the oil pan being far too low or axle angles being incorrect.

Has anyone here actually seen proof (pictures, video, or in person) that what I am asking for, and purchased, is possible in real life? Would really like confirmation before pulling my motor just to find out that the oil pan is lower than the cradle... or that I have to notch the trunk lid- in which case I may as well not use these mounts and brackets

Would appreciate some input- just looking for some reassurance before I bother to pull the motor and trans..

I have an F23 and Series III/ Gen V that would be going into the car. Full stack ZZP IC.

I also know a couple of people interested in doing the same thing and ready to buy mounts and brackets, but I have zero actual proof that it will work, and don't want to find out after pulling everything that I am wrong.. My current swap uses the old Purple Reign mount , but after putting in the F23, I could no longer use stock length axles. This is also another reason I want to change my mounts and brackets so that I can use stock length axles again, easier to source if I break them again, than having to get axle length modified.

Measure the current clearance from the supercharger to the bottom of the decklid support.
Measure the bottom of the oil pan to the bottom of the cradle.
Add the two together. This is your available clearance.

Measure the height of the full stack.

If you are not running an intercooler currently: Available clearance - height of full stack = X.X
If you are running a short intercooler currently: Available clearance - (height of full stack - height of short stack) = X.X

If the number is positive, then it can be done with custom mounts and possible clearance work to the driver side rail on the cradle.
If it is negative, then you have more work. You should not mount the oil pan lower than the cradle, but you can lower the cradle crossmember, then lower the engine further, but this will likely require more clearance work to the driver side cradle rail.

There isn't enough room in the engine bay to move things to the point of axle angles becoming an issue. Just very they are bind free in the full range of motion, then you are good.

[This message has been edited by fieroguru (edited 01-29-2025).]

Thanks Paul

I did buy customized brackets and mounts , and asked for photos prior to pickup to see how it all fit together. But I received zero photos... Oil pan depth.. Axle angle, etc. Hopefully I didn't male a mistake just trusting a verbal promise that it will work. Time will tell!

[This message has been edited by cam-a-lot (edited 02-01-2025).]

Who did you buy the mounts from? I'm guessing Brian Welch?

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88 Formula - 3800SC/4t65eHD
88 Coupe - 3800SC/4t65eHD
GBCT - 3800SC/F23

Correct. They look very well made. I just don't want to put all this work into putting a new motor and trans into the car with different axles than what I currently have , unless I am sure that it will work. This is the whole reason I asked for multiple pictures, but unfortunately did not receive any. I supplied an 88 engine cradle and F23 trans for the brackets and mounts to get made.

I was hoping there is someone on here who has installed them and can confirm that stock axles work fine with this setup and F23, axle angle, and that the oil pan is not sitting dangerously low. I do have a working and running engine and F23 in my car now, with my trunk lid chopped up to allow for full stack IC. I have a nice new trunklid available that I want to replace it with. But again, this is a ton of work, and unless I am 100% sure that it all fits, it is a big risk to remove my existing setup.

Thanks

quote Originally posted by cam-a-lot: Correct. They look very well made. I just don't want to put all this work into putting a new motor and trans into the car with different axles than what I currently have , unless I am sure that it will work. This is the whole reason I asked for multiple pictures, but unfortunately did not receive any. I supplied an 88 engine cradle and F23 trans for the brackets and mounts to get made. I was hoping there is someone on here who has installed them and can confirm that stock axles work fine with this setup and F23, axle angle, and that the oil pan is not sitting dangerously low. I do have a working and running engine and F23 in my car now, with my trunk lid chopped up to allow for full stack IC. I have a nice new trunklid available that I want to replace it with. But again, this is a ton of work, and unless I am 100% sure that it all fits, it is a big risk to remove my existing setup. Thanks

Yeah I am not sure why he has not supplied pictures yet. The trunk was chopped on the Choptop to make work. But in my eyes, that is the way to go and not worry about anything sitting low. Plus Fierorog mounts are the standard usually. Maybe he will chime in and show us. But with how low my cars are, I wouldn't want the oil pan any lower than it is now as is. Just my opinion though.

[This message has been edited by Rare87GT (edited 02-03-2025).]

Did the measurement in the past before buying the intercooler for my 3800SC swap. The short stack easily fit, the full stack would not have cleared the trunk lid unless the powertrain was lowered about 1". This was for an 87GT with WCF engine and trans mounts, With different mounts and a notchback body style the result may be different.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by Dennis LaGrua: Did the measurement in the past before buying the intercooler for my 3800SC swap. The short stack easily fit, the full stack would not have cleared the trunk lid unless the powertrain was lowered about 1". This was for an 87GT with WCF engine and trans mounts, With different mounts and a notchback body style the result may be different.

The decklid has to be notched regardless. My only take on this is if Brian Welch can make it clear and not have to notch with a full stack then why isn't he producing mounts for that option? I'm not taking anything away from him as he is a good guy and OG Fiero owner, but on the other side it seems almost like no one knows about this. I hope he can show pics and how clearances are. No one really wants to notch a decklid especially a custom one, but with limited options it is kind of the norm.

Agreed. This is the one and only reason I went all the way to middle of Michigan.. dropped off a cradle and F23. paid full asking price. I was told over and over and over again that this is possible, and that pictres are coming

Needless to say, I received zero pictures, so now I have to make tough decision as to whether or not I should bother to use the brackets and mounts I paid for, and drove a very long distance to drop off and pick up. Very frustrating, to say the least

thanks for your feedback

While I certainly don't have all the details, here are my thoughts, for what its worth...

Suppling the cradle and F23 for these mounts, likely indicates you received the first set of this particular design.

Since you didn't get the pictures requested, there likely is no one who could give you 100% certainty on fitment. You may not like it, but this could very well be reality.

Last night I refreshed my memory of the build thread for your car... I think you already have all the engine, supercharger and full stack parts installed, with the decklid notched. If this is the case, then in less than an hour of work you should be able to figure out how low the drivetrain needs to go.

Measure how much past the bottom of the decklid the parts are protruding and which side is the critical interference.
Measure the current crankshaft centerline to the bottom of the cradle.

Those two measurements will allow you to know "how low you have to go"

For reference:
Stock 88 with 2.8/getrag should be around 8 13/16".
I previously reworked a SBC/F23 swap, lowering its installed height about 1 3/8" and ended up with an installed height of 8 1/8", with it shifted to the driver side about 3/4".

If your drivetrain needs to go lower than 8 1/8", things will get very complicated.

If you get past this point, I can likely walk you through how to determine if the mounts will get you to the desired drop.

[This message has been edited by fieroguru (edited 02-04-2025).]

Thanks Paul, will do. Much appreciated

Years back Dave /Skitime installed a full stack. At Carlisle, I recall he told me that, as to not cut the deck lid, he just made custom mounts that lowered the powertrain. That was a long while ago. The Skitime car is in Colorado owned by Mike Valentine last we heard so if the owner sees this he may shed some light on this. Only an extra 1" of clearance is needed as that is the height difference between the short and full stack intercoolers.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 02-10-2025).]

quote Originally posted by Dennis LaGrua: Years back Dave /Skitime installed a full stack. At Carlisle, I recall he told me that, as to not cut the deck lid, he just made custom mounts that lowered the powertrain. That was a long while ago. The Skitime car is in Colorado owned by Mike Valentine last we heard so if the owner sees this he may shed some light on this. Only an extra 1" of clearance is needed as that is the height difference between the short and full stack intercoolers.

Except he did notch his decklid for clearance...

[This message has been edited by zmcdonal (edited 02-10-2025).]

Well I am EAGERLY awaiting the photos I was promised for the brackets and mounts I purchased for my F23/3800 combo that is supposed to use stock axles and be able to mount the motor with full stack IC without cutting into the trunk lid. I have my fingers crossed, as I really don't want to pull my existing engine/trans just to find out that this does not work

I cannot have my oilpan sit below the cradle- that is asking for trouble..

quote Originally posted by zmcdonal: Except he did notch his decklid for clearance...

I can only guess that Dave was boasting and to be honest about it, he was never eager to share much information on his build. Good point here about keeping the oil pan above the bottom of the cradle. I don't believe that on my build there is much more clearance there. My short stack works well but it uses a rather large heat exchanger and a gallon reservoir. The full stack would obviously be more efficient but by running Sunico 94 Octane gasoline my tune and boost (11psi) is very aggressive. There are no KR's at WOT to the redline.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Hey Dennis. Agreed

I guess for now I have to sit back and wait... the silence is deafening... I mean how hard could it possibly be to provide a few frigging pictures? Worst case scenario, I can sell off these mounts and brackets and whatever I get I can donate to Cliff. I am not willing to pull my whole setup just to find out that I still have to notch my trunklid- then I may as well keep my existing setup

Thanks everyone for chiming in. Live and learn, I guess... what a waste of time , gas and money...

Here's some pics of a non full stack intercooler car showing the clearance on the snout.
It's a good 3 inches below the decklid rib.
The top mount alternator clears as well.
The aluminum oil pan is level with the bottom of the crossmembers on the rear cradle.








I've got one here with a full stack I/C installed, but I can't find the trunk key at the moment.

[This message has been edited by olejoedad (edited 02-27-2025).]

Thank you, that looks encouraging.

Hopefully you are able to get the trunk lid open on the other one. I would very much appreciate it

Pls confirm with Brian that he used STOCK LENGTH fiero axles with my F23 and your 3800 block to create the mounts and brackets? My current F23 placement requires one shortened and one lengthened axle, which is a pain in the ass when I do break them (it has happened twice already). Would be great to just use stock length axles with my F23.

A few more pictures showing that there is no need to cut the decklid when using a full stack intercooler.

The decklid of this particular car was cut for the previous drivetrain install using mounts from another vendor.
The yellow tape on the cut areas highlight the original configuration of an uncut decklid.

Great info- thanks!

Are there any pics of the same car showing where the oil pan sits in relation to the cradle?

The engine was installed with the cradle and the oil pan sitting on the fab table, as we do with all swaps.

The car sits very low, it would be difficult to get a good picture.





In the first picture the camera lens is level with the bottom of the cradle, in the second picture the lens is below the cradle.

I hope this allays any doubts you may have as to the mounting system provided to you.

We have done engine swaps for the last 15 years, with no complaints from any customers, other than maybe taking too long to ensure a quality result.

[This message has been edited by olejoedad (edited 03-08-2025).]

It should be noted that the installation in the above pictures uses a 4T65HD rather than a manual F23, the the engine is mounted slightly higher in the cradle that your engine will be.

And, as you can clearly see, there is ample room to run a full stack intercooler without chopping the decklid, or having the drivetrain below the rear cradle rails and crossmembers.

[This message has been edited by olejoedad (edited 03-08-2025).]

Great info,, thanks again

You're very welcome.

Joe

Sorry for beating this to death- but one final question

I have found that with my existing 3800, when I replaced the Getrag 282 with a Getrag F23, one of my axles became too short, the other too long. This tells me that due to the physical size difference between the two transmissions, the mounting of the motor itself needs to slightly change side to side (move over toward the passenger side about 20 mm) To deal with this problem on my current setup, I've had to get axles modified, which is not a good long term solution

When I dropped off the F23 and 88 cradle at your shop, I asked very specifically that STOCK length axles and 88 rear suspension/knuckles to be used during mockup to ensure that the engine sits in the correct lateral location to allow for correct movement on both axles. (In other words, I did not want to have the same problem of too much side to side movement on one axle, and not enough on the other)

Can you please confirm that the engine mounts, brackets, and trans mounts/brackets I was provided DID take this into account? In other words, the engine placement is slightly different than if I was using a Getrag 282? This was the whole reason I wanted photos, to confirm that this was all done prior to final welding

Would appreciate a clear reply to this final question. I appreciate your help

Peter

I have no photo documentation, but the standard is to ALWAYS use stock Fiero axles on manual transmission swaps if at all possible.

The rational is that EVERY swap should not require customized repair parts to keep the vehicle on the road. If custom axles are required for a swap, the documentation of the axle build specs is provided to the customer.

[This message has been edited by olejoedad (edited 03-22-2025).]

thanks Joe, I know there are no photos unfortunately, but that does not answer my question

It was not that long ago, so Brian and his helper should still remember. Did you guys attach an 88 rear suspension to my cradle, and test fit using STOCK axles, knuckles, etc before finalizing mounts and brackets /welds, to ensure that stock axles will work with my F23 trans and new 3800 engine mounts and brackets? That the lateral movement for both axles is even?

I don't know in what other ways I can ask this question. I think I have been super clear- no? I need to know before dropping my engine and cradle /trans that this will actually work, and that I do no need to lengthen or shorten OEM axles. I think the only way to confirm this would have been during the fab process, and I VERY clearly asked for this. You guys indicated that you do have spare 88 rear suspension pieces and stock OEM axles to use during mock-up with my cradle and my F23 trans. You also said you have a spare 3800 engine block that you use to tie it all together before finalizing welds

This is what I am asking. Was this done?? I know there are no photos, but how can we know that the LOCATION of the mounts/brackets is correct (left to right) without actually test fitting with axles and knuckles, bolted together, and then checking for lateral play to ensure they are both correct?

If this wasn't going to be done, then why would I bother bringing a cradle and F23 trans 400 miles to Homer MI? I could have just taken my chances and order brackets/mounts over the phone

thanks

I don't know any other way to answer your question.

Why would the transmission NOT be located as per the STANDARD OPERATING PROCEDURE THAT HAS BEEN USED FOR YEARS?

Because you guys told me you did not have pre made brackets for F23- That is why YOU asked me to provide a trans... since you did not have one

How much more clear can I get?

DID YOU or DID YOU NOT test fit my trans and my cradle? Otherwise, why on earth would I drive all this way to drop it off?

More than happy to share all the emails if you wish, I have them

Sorry, but "verbal fit" ... or " We have done this for years" does not wash. You guys told me you do not have an F23 to make brackets with, so I provided it

I was promised that you would use it for test fit, and it would be recorded.

So .. for the 1000th time

DID My transmission and cradle get used for test fit? With the axles and rear suspension pieces , that was promised????

Happy to share emails

All I am asking is... was this done or not? ? Yes or no?

How much more clear and obvious can I be? I drove over 400 miles EACH WAY. Twice. I paid double what WCF or others charged. Why? Because I was promised a test fit, with the correct axles and suspension pieces, to make sure that all would work. Whe I came for pickp, I was given zero photos Just my cradle, trans, and the brackets/mounts separately. If this is all I was going to get, I could have just ordered them online from you or someone else and take my chances.


YES ?? NO? Was MY cradle and MY transmission test fitted with OEM axles and 88 rear suspension/ knucles, to ensure that it works? How much more clear and direct can a question be than this?

[This message has been edited by cam-a-lot (edited 03-24-2025).]

THE STANDARD OPERATION PROCEDURES ARE TO TEST FIT AND MOUNT AXLES AND SUSPENSION ARMS WHEN POSITIONING DRIVETRAINS.

Every set of mounts is custom made for the application.

[This message has been edited by olejoedad (edited 03-24-2025).]

Glad to hear it, thanks Joe

BTW, the mounts and brackets look very beefy and well made. Will post pics once they are installed

I'm sure that your swap will go smoothly.

If you have any more doubts about the cradle/mounts/ axles, bring your car, and all the bits for the swap over to the shop and we will install it for you at a reasonable price and with extreme attention to detail.

If, for some reason, any modifications to the parts the shop supplied to you are needed, there will be no charge for the install or the modifications.

You can contact Brian at 517-554-0452 for confirmation of this offer, pricing and scheduling.

Just backing up a bit and assuming my prior posts have been incorrect ; here are the heights from ZZ 's website. :
Full Stack Intercooler 2.24" H
Short Stack Intercooler 1.0" H

Net difference 1.25" higher for the full stack.
I don't believe that I have the extra clearance on my swap but I will measure tomorrow.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Hey Dennis. any news on this?

This was exacrlty my concern. even if I remove the entire drivetrain from my car and close the trunk, the distance between the trunk lid and the bottom of the cradle is constant. regardless of who makes the brackets and mounts, this distance can not change. The height of a 3800 SC motor with full stack IC is also a constant height. Irrelevant of who makes the mounts and brackets.

So this is why I have been trying to understand how it is possible that a 3800 SC motor with full stack IC , can fit between the trunklid and cradle without notching the trunklid. Custom mounts/brackets can not change the basic dimensions. The total engine height is fixed. The total distance between bottom of cradle and bottom of trunk lid is fixed. So how can custom mounts and brackets magically make this work without interference? I guess time will tell

quote Originally posted by cam-a-lot: Hey Dennis. any news on this? This was exacrlty my concern. even if I remove the entire drivetrain from my car and close the trunk, the distance between the trunk lid and the bottom of the cradle is constant. regardless of who makes the brackets and mounts, this distance can not change. The height of a 3800 SC motor with full stack IC is also a constant height. Irrelevant of who makes the mounts and brackets. So this is why I have been trying to understand how it is possible that a 3800 SC motor with full stack IC , can fit between the trunklid and cradle without notching the trunklid. Custom mounts/brackets can not change the basic dimensions. The total engine height is fixed. The total distance between bottom of cradle and bottom of trunk lid is fixed. So how can custom mounts and brackets magically make this work without interference? I guess time will tell

Just got back today will measure up. You will have an answer this afternoon.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "