hi I have a 1989 Firebird with a 2.8 V6. My question is can i swap it out for a V8? And what will it involve. I know I have to change the computer with the motor but what else will be involved?
Thanks

 

It involves a whole lot. Its been said alot around here that it would be cheaper to restore a v8 car than to do the swap. Do you have a v8 parts car? Youre gonna need one...more can be found by doing a search for v6 to v8 swap, this comes up all the time.

 

Yes you can swap it out for a V8. Do you want a 350 Carb? TPI? TBI? 305? LT1?Basics you need for a TPI V8 swap:

V8 TPI engine (cost varies depending on condition, etc.)
V8 Transmission (700 R4 usually retails for about $300-350)
V8 Wiring harness (get a complete engine, comes with it, if not, then expect to pay around $300 for one)
7730 ECM and V8 PROM (yours should have the 7730, if not comes with the complete engine, if not, around $60 for rebuilt)
V8 Fuel Pump ($65 approx.)
V8 Motor mounts ($20)
V8 Tach (free with a donor car)
V8 Oil gauge (free with a donor car)
V8 Radiator ($117 from auto zone roughly, lifetime warranty)
V8 Throttle cable ($20 from a GM dealership)
You'll need to move the brake line that runs underneath the engine, it sits right in the V8 motor mount spots.
I will agree with most people here, unless you are certain of every little thing you need, GET A DONOR CAR, you won't have to buy anything separately. If you know exactly what you want/need, then get a COMPLETE engine setup. If it's missing a few parts, you can bet you'll be spending some $$ to replace them. If you can find a donor car for $500, then buy it, and most of your cost is eliminated, versus buying an engine at whatever price, along with all the parts separately. The F-bodies had the option for V8, so once you get all that stuff taken care of, it's almost a direct bolt-in. My swap, total time involved took six 8 hour days. It was my first ever V8 conversion, and I had WELL researched what I needed to do, so I had very little surprises.

 

Well I see I was going to find a donor car actually. I already have the 700 R4 transmission. I just thought that it would be more than motor, motor mounts, computer and wiring harness. So basically I just have to find one with a V8 already in it and kinda do a paint by number?

 

That's more or less it. V8 donor car makes it a WHOLE lot easier.

 

Hey Quick_Trans_Am, What about the power steering lines, ect? I think someone mentioned you'll need the power steering pump from a v8...would a 305 parts car work?

ALSO: I already have the rebuilt 350, pre-87 TPI, ECM with original chip(needs a new one, right?), rebuilt v8 T-5...and the 305 TBI donor car I have I am letting a friend fix up and drive actually....so are the parts i need worth taking it back from him for a few measly mounts....are they really that rare a find?

 

The V6 and V8 power steering lines are standardized, at least on the 90-92 model years, as are the power steering pumps. I can't see them being much different on the other years. You'll need a new chip for that engine and trans combo. The one you have is set for auto trans + 305, and you need one for T-5 + 350. I like that combo . Sorry it took me so long to post back here, I've been busy and completely forgot.

 

That's cool. For the chip, I'm working on programming my own. I just have to order all the stuff and then I'll be on my way programming!

 

There are a couple ECMs used with the V6 cars and one of them will drive a TPI system. I don't recall which one and I don't even remember where I learned this tidbit of information. It was several years ago. But at least you have a starting point to search out some answers. I will post again if I remember where I got the information. They even gave me the serial number to look for but, of course, I don't have that any more either. I just know my car did not have the correct ECM.

 

ok the computer you speak of is the 730 ECM. You can find it on all 3.1 Multi-Port V6 cars. This is the same one that drives the TPI setup. Burning your own PROM is one of the best things you can do for the money. The software, equipment, etc. costs just as much as a "performance" aftermarket chip, and you can do it over and over again, and tailor it to your specific needs. Good investment there.

 

That sounds right. Good job on the technical info.