Originally Posted by mopar dave
What is your compression since you shaved .070 off? Jones spec a cam for my 511 awhile back of something like 277/287 on 112 with .700ish lift. Maybe that is what mine needs.

Bingo!
I like the numbers. What spring loads did he recomend? Getting that right is critical to getting the most out of the cam. A combo of too little seat and open pressure can rob you of a lot of the expected gains,
Not to mention tearing up the whole valvetrain . AMHIK!
I was told 225 on the seat for an Isky roller, and Monte (rip!) Advised me to put some serious spring in it.
So i went up to 330 on the seat and picked up .08 et in the 1/8 th mile! The big thing to consider is, how much load can your current parts take. The whole thing has to be engineered inside your chosen valvetrain. I had already gone to Jesel rocker system and that is why those big springs could produce results. The rockers, pushrods, and support system were up to the task.
But as you can tell from a previous reply, i put a lot of value on "getting it right" with enough compression and clearance for a bigger cam. That is why i made the comment asking about rhe value of newer pistons with a moderate dome. I think it is worth the change, just to get you the right base to work with here. But then each budget has its' limits.

Last edited by gregsdart; 03/04/22 05:57 AM.

8..603 156 mph best, 2905 lbs 549, indy 572-13, alky