I dont know what compression I want to run in my lt1. Is the horespower difference between 11.3:1 and 9.1 big enough to just go with the 11 and elminate possibilities of NOS and forced induction? The block is setup for 383 ci. I really would like to spray soon after I complete the motor and dream of one day supercharging. How big of a horespower difference will the compression make? thanx

 

About 20 HP difference
Try this site:
http://www.bgsoflex.com/crchange.html