im going to put a 4.3l vortec in my 1987 gt soon. Does anyone happen to know what transmission i could use that would still fit in the engine area

Almost any FWD transmission will fit with the 4.3 V6 swap. This swap has already been done with a 4T60, Getrag, 4T40 and I am working on installing one with the F40 6 speed.

I thought the 4.3 needed an adapter plate to mount to the transmission due to it having the sbc bolt pattern?

quote Originally posted by Macs86GT: I thought the 4.3 needed an adapter plate to mount to the transmission due to it having the sbc bolt pattern?

It does (well all but the 4.3L diesel)... but that doesn't keep the transmissions from fitting in the engine bay with the 4.3L.

[This message has been edited by fieroguru (edited 06-04-2010).]

If you are going to go through the trouble of installing a 4.3, then why not just install a V8? The effort is practically the same.

And the rewards are 33.3333% more torque output, but the fit is tighter. Weight and fuel consumption are both more, too.

quote Originally posted by Doug85GT: If you are going to go through the trouble of installing a 4.3, then why not just install a V8? The effort is practically the same.

Some of us already had a SBC fiero... before we did the 4.3.

The "work or cost" being the same between the SBC and 4.3 isn't really a factual statement. The packaging of the 4.3 provides much simplier/less expensive options for the accessory drive, exhaust manifolds and oil filter bypass and ends up being a simplier/lower cost swap.

The 4.3 is probably a better daily driver swap than the SBC since its 190-200 hp is quite moderate and far more predictable in rain/snow. It is strong enough to enjoy driving it and mild enough to enjoy driving it. It also helps that the MPG on my 4.3 was 24-28 on my daily commute and up to 32 on the interstate... vs 17/21 on my SBC car (both are fuel injected).

[This message has been edited by fieroguru (edited 06-04-2010).]

If a SBC Fiero is anything like a SBC S-10 2WD RCSB with no luxury options, then the SBC really is too much for sane fun. I did the Vortec 350 to my S-10, and now I'm switching it to a Vortec 4.3. The 350 was fun in it's own way, but it honestly was unnecessary. 4.3 plus a 75-shot of nitrous makes way more sense.

quote Originally posted by Isolde: If a SBC Fiero is anything like a SBC S-10 2WD RCSB with no luxury options, then the SBC really is too much for sane fun. I did the Vortec 350 to my S-10, and now I'm switching it to a Vortec 4.3. The 350 was fun in it's own way, but it honestly was unnecessary. 4.3 plus a 75-shot of nitrous makes way more sense.

I really enjoyed putting 40K miles on my SBC fiero before the engine was pulled and another V8 will be taking its place as $$$ allows. The fiero has the benefit of weight over the rear wheels to help in the traction department, but wheel spin was just a throttle push away anywhere in 1st or 2nd gear with 245/45/16 rear tires. It had 283 whp/317wtq and I loved to drive it back and forth to work and take it on long road trips. It was quite docile and had a mild temperment. I would like my next one to be over 350 - 400 whp... but it probably will not be as docile...

Your ZZ4 cam was much milder than what I used in my S-10, and IIRC, you're leaving the stock cam in your 4.3, while I'm going with a serious custom grind.

well i already have a 4.3l and i really would like to do the six speed transmission. any thoughts on supercharging it or would it be better to go with a turbo

the 4.3 is a good engine in its own right. in a fiero likely will be a great commuter or daily driver. it is basically a 350 sbc v8 minus 2 cylinders....literally. the rods are 350 rods. the front accessory drive and attachments are all 350 parts and the flywheel/flexplate is 350 parts. the bellhousing bolt pattern is same as a 350sbc v8. this was from a time when gm was in the business of using less castings or forgings for multiple outcomes. i am a gm certified master tech, and like the 4.3, the 350 and the 454 engine family. yes i even own multiple ls engines as well but my favorite is still my lt4 350 sbc v8 from a 1996 gran sport corvette with the hotcam option, makes 425hp stock. all forged bottom end is stock. great little motor. but again the 4.3 would make a good engine for a fiero. as far as supercharging or turbocharging with 20+psi boost i am not sure it would take that in stock form. good luck and have fun. my .02 mike in oklahoma

any tips on building the engine to support a turbo or supercharger. i know how to do alot of things when it comes to cars but as for actual parts and such im not that good at figuring out best parts to use during rebuild

mera7 is mistaken. The 4.3 rods have bigger big ends that are also narrower, compared against 350 rods. Yes, both engines use 5.7" rod centers, but they don't interchange.
But that has nothing to do with boost.
The '91 GMC Syclone and '92-'93 GMC Typhoon came with a turbocharged 4.3, which was rated at 280-285 HP, and 360 ft-lbs. In my files at work I have a complete list of all the internal differences between these and regular 4.3s, but I'm at home, so I can't post that right now.

[This message has been edited by Isolde (edited 06-05-2010).]

isolde thanks for the clarification. i wasnt telling them to try to interchange the 4.3 or 350 rods was just telling that the 4.3 and the 350 are very similar with the exception of missing 2 cylinders. the later vortec 4.3's changed by having a balance shaft but the early 4.3's were very similar to the 350 minus 2 cylinders. mike

he doesn't want to take the train...

I've seen a 4.3 in a Fiero. It comes off as a perfect marriage. If more power is in the cards, it doesn't take much doing. It's a cleaner install around that passenger side wheel well, and a lighter engine.

quote Originally posted by weaselbeak: I've seen a 4.3 in a Fiero. It comes off as a perfect marriage. If more power is in the cards, it doesn't take much doing. It's a cleaner install around that passenger side wheel well, and a lighter engine.

yup there are a few of us around lol

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87 Fiero GT 5sp with Vortec L35 4300 Turbocharged V6
Bully Stage 2 clutch
Syclone intake manifold and engine management with Moates adapter and chip burner
Air/water intercooler and Devil's Own progressive water/alky injection
50lb injectors, 3 bar map sensor, Walboro fuel pump and Jabasco Intercooler pump
LM1 wideband on custom manifolds and 3" stainless exhaust system
T31 P trim T04B H3 turbo and a S10 caliper conversion.
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