old school SBC swap (Page 1/4)
batboy SEP 12, 09:05 AM
My V8 Fiero with a worn out engine has sat untouched and neglected for 11 years. As a combination retirement and pandemic project, I have restarted my SBC Fiero swap. I have forgotten half of what I once knew. So, I will have questions for those that have done this swap before.

Teaser photo taken yesterday (see image). Just another old school 400 HP SBC 355. I can provide specs if anyone is interested.

First question is about water pumps, I bought a Meziere electric pump because I have one in my 2004 GTO that has held up well. Now that it's trial mounted on the engine (upsidedown), it looks big. Will this pump work? Has anyone else used one before?
Dennis LaGrua SEP 12, 09:33 AM
The old school SBC approach looks nice but is seldom used anymore for three reasons.
1. The tight fit in the engine compartment due to overall length. Using that water pump will necessitate cutting away a portion of the wheelhouse. To avoid this you can use a remote electrically operated water pump.
2 You cannot use a later day (stronger) GM automatic transmission. You can use the TH125 but it must be custom built to take the power and it limits you to three speeds.
3. If you go manual the Getrag is a poor choice as it will only survive long term with 200 ft lbs of torque. If you use an engine with twice the power you will need to change to the stronger F23 or F40.
Not trying to discourage you, just advise what needs to be done for a reliable swap.

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" 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 "

mafv8 SEP 12, 04:05 PM
I have a CSR brand pump on mine, it looks almost the same, its a tight fit vertically, depending on how low your engine is set into the vehicle. Length wise yo need to have a hole on the inner wheelhouse, maybe you can beat it down with a BFG for clearance? or mount remotely as previously stated.

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84SE, aero body, 4 speed and an injected 355 V8

batboy SEP 12, 04:57 PM
Dennis, you provided valid points and excellent advice. However, my Fiero already had a SBC swapped in 22 years ago when I bought it. Then, in 2010, I started building this engine (photo in post 1). The short block is done and I had already gathered most of the parts (about $4k spent on the engine). Long story short, I'm stubborn and committed to staying old school.

Previously, I had a belt driven water pump with the cogged pulley in the wheel well, but this time I wanted to go electric. So, there has been some cutting and trimming done. You mentioned remote locating an electric pump. I had not seriously considered that option yet. But, I think it might be a worthy "Plan B" if the Meziere doesn't fit while mounted on the engine.
batboy SEP 12, 05:14 PM
MafV8, thanks for the info. So, my electric water pump perhaps maybe might fit with enough tweaking.

Here's what it looks like now. So previously, some trimming (hacking) was already done.
reinhart SEP 13, 12:42 AM

quote
Originally posted by Dennis LaGrua:

2 You cannot use a later day (stronger) GM automatic transmission. You can use the TH125 but it must be custom built to take the power and it limits you to three speeds.




Countless people have swapped in a 4 speed automatic TH440 into a stock Fiero V6 or 4 cyl. If those are interchangeable with the L4 and V6, why wouldn't it be interchangeable with the V8 if the TH125 works with the V8?
batboy SEP 13, 03:57 AM
I'd rather not have a big debate over transmissions. Yes, you can swap in a 4 speed OD auto like what the Grand Prix GTP used. Seems like you have to change axle length, etc.

The little TH125 in this car held up like a champ for many years, so I'm going to freshen it up and keep using it. They are tougher than most people think. Some folks have different opinions.

Back to the water pump, after some measuring and eyeballing, I think the Meziere unit I have will fit, if I do a little more wheel well trimming. If not, I'll mount it remotely and get a pair of block adapters.

Next problem, the dogbone bracket on the engine appears to be homemade and might not fit onto the intake manifold I have on the new motor. Also, looks like rodents have chewed up some wires.

The fun never ends.
V8Steve SEP 13, 07:58 AM
I ran my Getrag for around 26K miles with a ZZ4 and no issues whatsoever.

I built mine in 1999 and drove it until 2007 when the ZZ4 cracked the block. Then it sat until 2015. This year I finally finished it with a fresh 355 from a seasoned block. Yep, my first version had the Gilmer belt driven water pump, just like yours. Now it's a Meziere pump.

We're in the same boat and I'll be glad to help you out with any questions.

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88GT 355 CI Sequential Holley HP Multiport EFI, AFR milled 180, Dyno'd at 427 HP, 360 WHP, F40 6-Spd
anderson@gdsconsulting.com

batboy SEP 13, 11:14 AM
Thanks Steve, if I get into a bind, I might just PM you. I feel better knowing you got a Meziere to fit.

MafV8 used a CRS electric pump. I looked up some photos and that pump looks a lot like the Meziere.

I'm in the process of disconnecting the old engine and getting ready to drop it out. I'm taking photos, using painter's tape to label stuff and putting small parts in ziplock baggies.

But, the good news is the dogbone mount will work fine on the new engine, so I'm sanding off the rust and will paint it. I have poly bushings ordered for the dogbone.

So, progress is being made even if it's moving at a snail's pace. But, the throttle linkage is cobbled together. I might need to figure out something better.
fieroguru SEP 13, 07:21 PM

quote
Originally posted by Dennis LaGrua:
2 You cannot use a later day (stronger) GM automatic transmission. You can use the TH125 but it must be custom built to take the power and it limits you to three speeds.




quote
Originally posted by reinhart:
Countless people have swapped in a 4 speed automatic TH440 into a stock Fiero V6 or 4 cyl. If those are interchangeable with the L4 and V6, why wouldn't it be interchangeable with the V8 if the TH125 works with the V8?



Dennis simply doesn't know what he is talking about

The SBC has been paired with just about every FWD automatic transmission. 125C, 440T4, 4T60, 4T60E, 4T65e-hd, 4T80, TH325, & TH425 - most are documented with build threads on PFF. There is nothing specific about the SBC that doesn't allow the use of any of these transmissions. Like every swap, there are specific details to work through, but every one of these transmissions has been used with a SBC in a Fiero.