[72LuxuryLeMansLa.]

Originally Posted by 70 Dream

I have to make my rebuild decisions soon. What I want is a stock rebuild for my 400 cid. We all know the stock 10.25 CR is too high for today's gas . . . . but if I go for say a 9.5 CR, will that be too high, even for 93 octane?

I am supposed to tell my engine builder what I want, but I am quite sure that I don't know what it is that I'm supposed to tell him.

I'm not even sure what questions I should be asking in this post. Do I want the highest CR I can get away with on pump gas? If yes, what is it? Do I pick a lower, safer CR that I won't have to worry about? If yes, what is it? How high is "too high?" And is there such a thing as going for a CR that's "too low?"

Next to cam selection (totally confusing), this is my most frustrating issue. I don't really care about performance as much as streetability and reliability.

Thanks for any and all opinions . . . . .

I'm certainly NOT an Experienced engine builder. but if you have some decent automotive knowledge, this article may help you as much as it did me to understand what steps to take to build an engine that will meet your goals.

This is written by Jim Hand:http://www.pontiacstreetperformance....mpression.html