jcab12

I am looking at an 82 trans am, 305, 4 speed. Nice car, but the 305 doesn't make too much power. I found a semi-local 78 L82 out of a vette that can be had for a decent deal, with a th350 trans.

1) I love and would very much want a manual, would the 4 speed (T-10?) work with the 350 without instantaneous detonation?
2) would the 350 work with the car? I am fuzzy on the "chevy vs pontiac" differences.

I have had a 350 before, an 87 GMC stepside with a "texas 300" 3 speed that blew and was replaced with a th350 with overdrive.
Thanks for the advice!

Drew

iTrader: (58)

Well, they're both Chevy's so that's not a problem. The problem is the 78 is a driver's side dipstick motor. It won't fit with the stock exhaust manifolds. Might have problems with the earlier engine using a 168 tooth flywheel, instead of the 153 tooth on the 82. Easy enough to change the flywheel, but the starter is also different. The block might be drilled for both starters, or not.

Beyond all that, the 350 from a 78 Vette probably makes the same or less power than an 82 305. They weren't great engines. It'd be kind of dumb to go through that kind of work for a 70's vintage engine. Not when you can go newer and get a 1pc rear main seal that won't dump oil all over your driveway, a 1pc rubber oil pan gasket, a dipstick tube position that would work with the stock exhaust manifolds, a roller cam that won't go flat running modern oils, likely better quality control, etc.

BTW when someone says "I've got a Vette motor" it almost always really means "I've got a truck, monte carlo, caprice, boat motor with the same cubic inches as a Corvette motor".

jcab12

Well, the motor was pulled out of a corvette, which is why I think its from a vette haha. The 1982 305 that came in the trans am only produces 145hp and 240lb.ft (per wikipedia) when equipped with the 4 speed manual trans. The engine that I believe to be an L82 is supposed to produce 220bhp and 260lb.ft which is significantly more than that of the 305. Which is the reason behind me thinking about this swap.

Drew

iTrader: (58)

Oh. Hmm, Ok just forget what I said.

Sure, maybe it made 220hp, 40 years ago in a Corvette. Sucking through a Corvette dual snorkle aircleaner, blowing through Corvette manifolds, dual exhaust, etc. How much wear do you suppose it's accumulated in 40 years? How much is the power going to go down when you bolt on the single snorkel aircleaner off the T/A, and the cast iron 305 manifolds with the stock 2.25" exhaust and restricted catalytic converter. How much more power is it going to shed when the cam starts wiping lobes because modern oil doesn't contain zinc?

No offense, but in the real world, by the time you get done putting that engine in an 82 T/A, it's probably not going to be as much of a difference as you are thinking. In reality both the 70's 350, and the 82 305 are both garbage. I just wouldn't waste the time and money to swap a slightly less crap engine into the car. If someone gave me a running 350, freshly pulled from a 78 Corvette, it'd be on Craigslist for a few hundred dollars before I went to bed the same night.

jcab12

I understand it will have some power loss over the years, as with anything old. However, she would breathe through a better intake and out a better exhaust than the t/a. Probably a straight pipe with some nice headers. Also, even with power loss I am sure the 350 has more power than that 305.

I am wondering what it would take to put the 350 in the car. Would the 4 speed bolt up or would I need to use the 350? Would the mounts from the 305 bolt to the 350? What wiring would I need to acquire? You said the dipstick would cause an issue with the stock manifolds, would the stock t/a manifolds even bolt up?

If you don't recommend this engine, what do you recommend for this swap? The 305 just doesn't produce enough power.

dmccain

iTrader: (2)

I can tell you this. I had a couple friends with late 70s early 80s Corvettes back in high school and my Formula would outrun them and outrun them badly which tells me they didn't have much power. My Formula was a lightly modded LG4 that only mustered high 14-low 15 sec 1/4 trips. My neighbor ran his mint 79 through once and it only trapped a 16.4 in the 1/4. Take Drews advice and try to get a modern roller engine if you can.

Drew

iTrader: (58)

Mounts and the trans should bolt up as long as you use the right starter, flywheel, etc. Things get a bit complicated when you get to things that bolt to the heads, since not all SBC heads have holes drilled and tapped for thirdgen manifolds and accessory brackets.

Get an approximately 1987 or later 350. Starting about 86 GM switched to a 1 piece rear main seal that virtually doesn't leak. Around 1987 the started casting all the blocks with provisions for roller cams. Generally trucks didn't get roller cams until the 90s, but at least the blocks are capable of having the holes drilled and tapped. Probably the most promising donor thats easy to find is the 96-98 Vortec 350. You can get a new GM Vortec crate for around $2,000. Vortec heads are some of the best stock small block heads GM has put out. They require a special intake, but they are easy to find too. Swap out the truck cam, and valve springs with a good aftermarket roller cam, and bolt on a good carb, and you've pretty much got the 330hp GM 350HO crate engine.

jcab12

Thanks for all the advice man. I was thinking vortec but I wasn't sure what the vortec needs for wiring and management and was looking for something a little simpler. I do very much like the 87 350, it was in my first vehicle and I remember it being simple. I assume the wiring that is extra in the 87 350 would be wiring for the tbi? When you say bolt on carb, do you mean on the vortec? Weren't those motors also tbi?

Tuned Performance

iTrader: (92)

Sounds like you have crossfire ?
If that’s the case you need to tune in order to keep the x fire.
Dynamic efi has a ecm that would aid in tuning or you can use a 88-91 truck 1227747 ecm. There is little support for tuning your stock ecm.
I agree with the guys above you don’t want a 70s vette engine low compression small cam engine.

jcab12

I don't own the car but am looking into it and it is more than likely going to be a 305. The one I am interested in is an 82 305 4 speed so I do not think it would be crossfire. What is involved in putting that type of ecm in an earlier third gen?

Tuned Performance

iTrader: (92)

You could get a harness from a 88-92 tbi f body car. The connector c100 would need to be repinned. You would also need a higher pressure pump in the tank. Some early thirdgen shad a pusher pump in the tank. I’m not sure if you can use a non pusher pump tank with a high pressure pump I’m sure drew knows.
Bye high pressure you only need 14 psi to run tbi with a return to tank line.

Drew

iTrader: (58)

All CFI cars were autos, so it should have a Quadrajet 4bbl. It's a computer controlled unit, but as long as it works on the 305, it'll work on a 350. Same goes for the distributor. The other way to go would be to get a Quadrajet for like a 1980 Caprice with a 305 or 350, which would be almost the same as the 82 carb, but without the computer controls. Then replace the distributor in the 82 with one from the Caprice, or an aftermarket vacuum advance replacement. Pop the bulb out of the Check Engine socket in the dash, and you'll never know the computer controlled bits are gone, and it'll be like any other oldschool carbed car. All the wiring you need will already be there, unused plugs for the CCCarb can just be left hanging.

Gotta be a bit careful with intake manifolds. Thirdgen hood lines don't leave much extra room. Stay away from high rise intakes, and carb spacers and it should be fine.

Drew

iTrader: (58)

Back in the day, GM performance parts developed an emissions legal set of parts to put a ZZ4 crate motor in a LG4 305 Camaro. Now being emissions legal, the conversion used the stock computer controlled carb, later high flow manifolds and exhaust, etc. The Vortec heads would change the intake required but everything else would be about the same. It's worth looking into just to see how GM recommended doing a later 350 swap.

http://www.superchevy.com/how-to/eng...onversion-kit/

http://www.camarotech.com/engine-ZZ3.html

https://paceperformance.com/i-625559...0-package.html

https://www.thirdgen.org/forums/engi...tructions.html

Lots of results when you google the topic... Combos of "ZZ4 camaro conversion" and various early thirdgen years like 82, 83, etc. Tons of good info out there