I am running a stock headed 306 cammed LT1. It has the stock rods/pistons/crank, and 2 bolt mains. I did however install arp main bolts, arp waveloc rod bolts, arp head bolts and all new bearings and hellfire rings. I am running Crane dual coil springs with modifed heads for the spring seats. I have comp nsa pro-mags (1.6), cm motorsports pushrods and comp r lifters, and a cloyes double roller.

I know that I have never felt the car stop pulling, it is still pulling when I shift (even at 6400rpms on the stock tach).

I just want to know what you guys suggest shifting at to get the best performance without sacrificing the engine.

Thanks,
James

 

did you have to get it cleaned up or any machine work done to the block for that? how much did it all cost you? i'd imagine you can spin it up to 6500 safely but i dunno...

 

Had the block honed (not bored, still running stock bore), crank was polished, rod caps were fitted with the new bolts and the caps were resized. The heads got a valve job, machined for the spring seats, and milled/plained.

Dunno really how much I spent.

 

you have a big cam, rev it high or switch to a smaller cam that doesnt need to go as high. you would have to rev it to ~6800 to get the most out of that cam

 

Ya, I know the cam is a high rev'ing cam, the question is more about how high my motor can go.

-James

 

Your limiting factor is going to be that cast crank & stock PCM. Short burst to 7k should not be a problem for you so long as the assembly was done correct. From what you've described thus far it looks good. I think you'll run out of PCM first, LOL.
My .02
Steve...

 

If it were me, I'd let it sing once in a while. It looks like you have a pretty good build, and how often are you really going to need those extra 3 or 4 hundred rpm?

 

I did the same thing and my motor blew up for one of two reasons. The weak stock piston let go and just fell apart. Or the 230/236 and weak *** cm612 valve springs combined with 6200 rpms floated the valves and it hit the piston causing it to fall apart. To sum it up, my block is shot, heads gone, cam ruined, so basicly everything but the intake was ruined. Im pretty sure that it was the agressive cam and the 612 springs that caused it though.

 

how much did you pay to get the bottom end reconditioned like that?

how much was labor, parts etc. ?

would i be able to use a new set of rods and pistons and not have to re-balance?

 

See above.

 

neither one is true. (no offense). the stock 1 piece lt1 cranks are very good and will handle a ton. unless a crank is a bad crank or a cheap brand (which a stock lt1 crank is not) it is all about the balance. I've seen a few stock bottom ended lt1's rev to 7000 while drag racing. I've also seen a stock crank bend at 5000 on a 150 shot. since his crank has new bearings to ride on and has been machined, I'd assume the motor is like brand new. I'd say its safe to turn 6700 and 6800 on occasion, however i would not want to hold that rpm for any length of time to be safe.
as for the pcm, it's limit in rpm is 7200 without help of a piggy back unit. it will supply fuel and timing right up to that 7200 without a problem. Exception being cars that require more fuel than the pcm can issue, but those are typically high boost cars.