Alrighty, as some of you have seen, I just recently aquired a fairly beat 92 firebird v6. The motor has been having some issues, so instead of busting my ***** trying to fix it, I feel like I really want to swap a v8.

Ideally, I'd like to just swap to a 305, so I don't initially kill myself with my first 200+ hp rear wheel drive car.

anywho, onto the questions I have for you all.

First off, there's a junk yard here in northern va, called pick a part, I'll be getting all my parts here, pulled by myself and a friend of mine. Any engine is a flat 200, no matter the condition, so I'm hoping to find something nice that doesn't need too much polishing. The junkyard lets you take everything for the motor:wiring harnesses, motor mounts, etc. included in the price. if needed, a tranny is findable and buyable, but this leads me to my first question:

Will my v6 overdrive transmission work for a 305? I read the sticky at the top, and it said it would be fairly weak, but i also believe I read in another post that the v6 will work just fine. Can you clarify?

I know I may need a v8 ECM, but the sticky said i may just have to swap my PROM, depending on the v6 and v8. I'm hoping to find a 305 from a 3rd-4th gen, so how would I tell if I need to swap them out? Is swapping the PROM easier than the ECM?

As for the tachometer, I should just rip that out of the v8 car, right? Since I'll be getting the wiring harness in tact and included, that makes it easier to make this emissions legal, right?

 

I assume you mean a 5-speed manual transmission. V6 automatic transmissions simply won't work.

You will need a V8 bellhousing, flywheel, and clutch pressure plate. I hear the S10 V6 clutch disk has the same splines as the V6 3rd gen transmission, and is only slightly smaller than a V8 disk (10" vs. 10-1/2"). I haven't verified any of that myself, and couldn't tell you which S10 clutch disk to ask for (should be able to find that info on the Transmission/Drivetrain forum). Just remember the reason there are fewer splines on the input shaft of a V6 T5 than a V8 T5 is that the V6 shaft is smaller - and therefore, weaker. It would be much better if you could get a V8 transmission.

Usually it is easier to use the ECM that goes with the engine. If you can get it free with the engine, then by all means do that. If you get a 4th gen engine, you absolutely will have to get the PCM.

Getting the tach (or whole instrument cluster) would be easiest. I'm not sure if the earlier clusters fit in the later cars, perhaps someone else can clarify that (the "newest" 3rd gen I've had is an '86 donor car).

 

thanks for the reply

I think I will just pull out the transmission from the car I get the engine from. I'm only going to be looking at 3/4th gens, just to make sure I get direct swap parts.

If at all possible then, I should grab the tranny, ecu, and motor from the same cars. Gotcha. If I get a 4th gen dash set, how hard is it to mate everything together? If it's that much of a pita, I might just order one if I can't find one.

And of course, get a v8 exhaust. Now, I have my ways around emissions checks, seeing as how it's not required for my area, so should I go with a straight pipe followed by a muffler? I'd use a muffler just to quiet it down so i don't wake the neighborhood by my late night adventures