350 LT1 compression...Lower it?

[TDW]

I took the engine from my 70 Z28 to the machine shop. It needs .030 over pistons. I bought a set a while back. TRW, GM replacement pistons. The engine builder wants to cut the pistons compression ratio down to 9.3 to 9.5. I don't drive the car too much,so I am thinking about leaving them at 11.1 and running a Crane Blueprint Series factory spec LT1 cam. Any thoughts are welcome. What have you guys with this engine done at rebuild time? Engine builder says it won't run on 93 octane, but my L78 and my 302 both run good on 93 pump gas.

[Chevy454]

Follow *your* gut, Tony...I'll betcha a barley pop those TRW pistons would spec out too short [as is] and you'd be low on compression, especially if you haven't gone hog wild with decking the block...tell him to leave the pistons as is, cc everything, and I bet you'll see 10 to 10.5:1 *max*...also, that Crane cam is the way to go...

[COPO PETE]

I'll bet on it being 10:1 tops. If your really concerned, cc your head to see how close it really is to spec.
Peter

[Salvatore]

I agree with both these gentlemen. My 302 came out to 10.4:1 with TRW's and the head work. I used the Crane blueprint cam also. Never have problems with gas or heat. Sam

[TDW]

Thanks guys. That is excatley what I wanted to hear!

[YENKO DEUCE REGISTRY]

I used the TRW's with a .030 overbore, I know it's not 11.0:1 - and it will run ok on 93 octane, it likes a little more, but will dawdle around on 93. Don't go with 9.x's