I've brought this issue up on these boards several months ago, but I now have more information regarding the engine that I was thinking of swapping into my LB9 305 IROC. After checking some casting numbers, this is the 350 engine that I have to work with:


Block (3970010): 1972 Corvette, 200 & 255 HP, 4 bolt mains

Heads (333882): 74-76 Camaro & Z28

Intake: No casting number found, just labeled as an "Edelbrock Torker"

Exhaust (3932376): 67-70 Chevelle, Camaro

Crankshaft (3932442): 68-81 Passenger, Camaro, Chevelle, Nova; cast iron, large journal

The engine has a Holley 660 CFM carburetor on it. A website that I found said that with this combination, the engine produces around 260 HP with a stock GM intake.


Now that I have more information about this motor, what kind of potential does it have compared to my LB9 305? I would want to keep my TPI setup -- would this intake bolt up to an older block and heads? Keep in mind that (for some reason) my '86 LB9 has center-bolt valve covers, which weren't supposed to appear until 1987. I'd take what I could from my 305 and put it on this 350 (distributor, etc). I would certainly get into PROM burning, basing it off of the '89 ARAP code.

All in all, would this be a decent swap, or would I be better off upgrading my 305?

 

It's not a "Vette" motor, it's a POS. See this link for a "Vette" rant
https://www.thirdgen.org/techbb2/sho...hreadid=115165

The 010 casting is one of the most common of the 70s 350 blocks. It came in everything from Nova 2-barrels to trucks to Z28s to Impalas to vans. You would do better to think of it as being an Impala motor, because the odds are probably 1 in 4 that it came from one of those, 1 in 6 that it came from a truck, 1 in 8 that it came in a Chevelle, 1 in 10 that it came in a Nova, and about 1 in 150 that it came in a Vette. It's the same motor as a 74 Impala 2-barrel, except with whatever intake manifold stuck on it. Same garbage heads, same ordinary 305/350 crank casting, just plain ordinary garden variety junkyard 70s smog schmutz.

Throw the heads in the trash. Same for the exhaust manifolds, the intake, and probably the pistons which are probably dished. The block is a decent casting, if (big if) it doesn't have the starter bolt problem where the bolt holes are drilled too far from the crank, and if the lifter bores all point straight at the camshaft. Any 70s Chevy block has a significant probability of having one or both of those defects. About 10-15% of that casting had 4-bolt main caps installed in them, so you might possibly have that. The crank is an ordinary cast crank. All in all, if the block is OK, you have the short block hard parts (block, crank, maybe rods) for a 400 HP motor, safely.

I would not use your 305 heads on it, period. Others might with extensive porting. My recommendation would be to start out with some better heads than either the unknown ones on your motor or the 882s. Even if you use the 882 heads which will give you 8.5:1 CR with the usual flat-top pistons, putting the TPI on it would downgrade it from the 220 HP or so that you might get with a carb, to about 200-205 with the TPI. I would not recommend swapping it into your car like that. On the other hand, it's a 350 block, same as any other 350 block as far as that goes, except that whatever magic is in it from being listed as possibly having come from a Vette might be worth .... oh, maybe .001 HP. Put a set of flat-top pistons in it and a set of 350 TPI heads, you'll get the 230 HP or thereabouts that a 350 TPI delivers.

 

Thanks for the reply, RB83L69. I'll take what you said into consideration... I still want to see what some other people's opinions are on the matter. In my casting number book, I did notice that the block came on a bunch of other Chevys. However, I do know that it definitely came from a Corvette because that's the car my dad got it from back in the mid-80s... it isn't speculation.

 

Not sure why you need other opinions...

The Torker is a single-plane, open-plenum, 2500-6000 RPM manifold. Most any current aftermarket dual-plane will out-perform it.

Pretty much everything else was said by RB. Unless your dad knows for a fact that the engine came from the factory in the car it was taken out of, the "Vette" part means nothing. Since it is a mixture of parts, especially non-performance parts, then it means you got a free 350 block.

You're probably better off upgrading this 350 than you would be upgrading your 305. Just work on getting the parts to match up, concentrating on making it work with the TPI.

 

I would save up for a goodwrench crate engine. IMHO That car is to nice for that old 70s stuff.