Picking up project fiero. Need help deciding on engine/trans swap (Page 1/3)
spartan_chaz JUN 17, 11:08 AM
This may be a long read...So I apologize ahead of time, but I need some help with details and deciding which route to take....

So I will be picking up an 87 GT in the next couple weeks. This is going to be a COMPLETE overall restoration of the car....as in everything will be replaced, if it cant be replaced it will be fixed. I also plan to do an engine and trans swap to something better, more powerful, more reliable, and something that will last a good long while.

So....for the meat and potatoes, I am attempting to decide between 3 swaps. Honda K24, 3800SC, and LS3. If I do go with the LS3 or 3800SC I am then trying to decided if I should go with the F40 swap.

So.... pros and cons

K24 with K-series Honda trans:
Pros:
All engine/trans parts are Honda. So VERY easy to find replacement parts and aftermarket is insane. So no worries on mods to get more HP from it.
Super Duper reliable
great gas mileage cuz Honda
super easy to work on inside the engine bay
Honda parts are like Legos

Cons:
not a common swap so swap parts need to be custom made

3800SC:
Pros:
well known and documented swap
possible swap parts being sold? (I'm having issues finding someone who still makes and sells parts for the swap. can anyone help with that?)
can be VERY reliable
can make decent power with mods
fits well in the engine bay
fairly simple to work on after swap

Cons:
slowly losing aftermarket support over time. Which may make replacement parts hard to find eventually.

LS3:
Pros:
MORE POWAH BABY! (stock power is plenty enough)
cool factor

Cons:
swap parts????? (same as 3800SC still trying to see if someone makes and sells swap parts?)
cramped engine bay for working on it
heavier modifications to get working.

Then there is the F40 Trans swap:
Pros:
6 gears for good cruising when i take a road trip with the car
more modern trans
Mates directly to 3800SC?

Cons:
Swap parts???? (who even does mounts and brackets? and what clutch/flywheel combo needs to be used for either 3800SC or LS3)

These are the major point I'm trying to figure out....that way i can set a good plan in motion. I would GREATLY appreciate the help tracking down who may be making any of the mount, brackets, adaptors, kits, whatever for any of these swaps! That alone may help me narrow the choice down so i can finally get rolling on this thing lol
msweldon JUN 17, 12:05 PM
Not sure if its your cup of tea but don't forget the LQ1
spartan_chaz JUN 17, 12:07 PM

quote
Originally posted by msweldon:

Not sure if its your cup of tea but don't forget the LQ1



The engine I'm getting with the car is actually an LQ1 and it currently out of the car and a bit torn apart. I thought about it but really wanting to go with something i can get more power out of and a bit more modern tech.
fishsticks JUN 17, 01:53 PM

quote
Originally posted by spartan_chaz:


LS3:
Pros:
MORE POWAH BABY! (stock power is plenty enough)
cool factor

Cons:
swap parts????? (same as 3800SC still trying to see if someone makes and sells swap parts?)
cramped engine bay for working on it
heavier modifications to get working.



If I was going to start from the beginning again this is the direction I would go.

These is a swap kit available but it's $$$. If you're good with fab you can probably make most things yourself.

LS3s are also available in 6.2L trucks as the L92 and L9H with VVT, and probably for less money. Same aluminum block and rec port heads.

The LS4 is also all aluminum and set up for FWD applications already. But loses about a liter of displacement.

[This message has been edited by fishsticks (edited 06-17-2021).]

spartan_chaz JUN 17, 02:21 PM

quote
Originally posted by fishsticks:


If I was going to start from the beginning again this is the direction I would go.

These is a swap kit available but it's $$$. If you're good with fab you can probably make most things yourself.

LS3s are also available in 6.2L trucks as the L92 and L9H with VVT, and probably for less money. Same aluminum block and rec port heads.

The LS4 is also all aluminum and set up for FWD applications already. But loses about a liter of displacement.




Could you provide a source/link for the kit for that swap? I have searched and havent been able to find any up to date info
fishsticks JUN 17, 02:53 PM

quote
Originally posted by spartan_chaz:


Could you provide a source/link for the kit for that swap? I have searched and havent been able to find any up to date info



V8Archie makes the LS kit.
spartan_chaz JUN 17, 03:08 PM

quote
Originally posted by fishsticks:


V8Archie makes the LS kit.



Is he still doing the kits? I did find multiple places that said he is retired or no response. But none that says he still is recently.
fishsticks JUN 17, 03:33 PM

quote
Originally posted by spartan_chaz:


Is he still doing the kits? I did find multiple places that said he is retired or no response. But none that says he still is recently.



My understanding is he is still selling kits, but no longer doing the full conversions.
spartan_chaz JUN 17, 03:40 PM

quote
Originally posted by fishsticks:


My understanding is he is still selling kits, but no longer doing the full conversions.



Neat! Well I’ll reach out to him through his site and see what the cost would be! Other issue would be tracking down the LS3 and f40 in the current market…
fishsticks JUN 17, 04:31 PM

quote
Originally posted by spartan_chaz:


Neat! Well I’ll reach out to him through his site and see what the cost would be! Other issue would be tracking down the LS3 and f40 in the current market…



Anything is going to be tough right now. LS3's are extra tough (ask me how I know). IMO the truck 6.2 is the way to go for availability. Put a cam and springs in it, reprogram the ECU and have 500hp on tap. I have a 330K 6.2L truck sitting here with a bad 6L80 and was >this< close to pulling the motor out of it for Fiero shenanigans.

Power is so easy to make these days, especially with turbos.

Admittedly, I'd love to see what a K24 setup would do in a Fiero as well.