sandman92084

Ill start off saying i've got a 68 z28 302 and I love this motor. Has great power and sounds great at 7500 rpm. I want to build one for my 87 and have some questions. I've got an 89 block 1 piece rear seal and factory roller cam. I also have a 95 caprice 4.3 crank, same as the lt1 but with a 3" stroke. Will this crank fit in the block without machine work or adapters? I do know that a regular small block crank needs a special flywheel to work with a t56 will using this crank let me use a stock lt1 flywheel? The most important question though is will this crank handle 400 hp and 7500 rpm? I would love to hear from anyone with experience with anything like this.

shanep1991

i dont think you quite understand what youre asking, from what you said youre trying to put a v6 crank in a v8, if you want a cheap 302 then go find a 283 crank and put it in your 350, its not really worth it though, sure they "rev better" but you will probably just lose power and theres no point to want to rev way up to 7500 rpm, get a nice roller cam for your 350 and redline at about 5500-6000 and you will be way happier with the power you would get, just cause you can rev way up to 7500 rpm in your 69 camaro doesnt mean you have power all the way up there, its just putting unnecessary wear on the engine

torque_is_good

interesting

high compression low displacement engine that put out around 300HP to the crank measured the old way without accessories

why do people try to pull the "old school" ploy?

Old school is just that; old school.

Heck, look at the 4th gens including the LT1's

with a simple computer tune, a CAI and some headers you have beasts that both the LT1 powered and LS1 powered vehicles outperform that 302 powered Z and get better mileage. With those mods both engines are over 300 crank HP measured in todays method.

Also, better torque curves so the engines are better for the street. Any new half decent crate engine will outperform the wonderful 68 302

sandman92084

I was really hoping to hear from somebody that had done something like this before. I had parts laying around and wasn't really worried about torque curves or buying crate engines and tuning fuel injection systems, I just wanted to know if they would work together. My 68 is rebuilt to original and peaks 307 hp at the wheels at 7200 rpm and still gets 20 MPG with 3.73s and a 4 speed when I want to cruise so with a t56 gas mileage wasn't a issue I was worried about either. And yes the caprice 4.3 is a v8 go research the L99 LT based engine, and a 283 crank will not fit in a 350 block the mains are different sizes.

kanexpl

I built the engine. Used 94 l99 crank and rods in 350 roller block. Used kb 105 pistons with 1/16 rings. The cam was comp cam 08-302. I used a 6 inch balancer. It cost me 400 to balance it. It had 13 inches of vacuum at idle. Even with the ported stock tpi intake, it needs at least a 3000 stall convertor. The motor lugged bad with 4.10s in overdrive at 55 to 65. I had a 2000 stall vette convertor. The combo is for manual trans only. The car would blow the tire off mid way thru third, hook up and be done. No mass to keep going. The 700 would only down shift to second and lug like a turbo car. You need a one piece crank flywheel. The rods are powered metal, suppose to take 450 hp. The crank weights 43 pounds. 3 inch stoke with 2.45 mains, I don't think it's going to break. The motor reved great to 6800 ( valve float). I still have the rotate assembly. It got some metal from dist gear. Needed to get turned. I built a 350 this time. Should have built a 383 the first time. With a manual combo would work better.