I have used it with smogger shortblocks all the way to true 10:1 Yea more compression runs better but his application will work great with that cam advanced a little like I mentioned---It will run fine with less CR than they advertise--they gotta put something in that blank--the 6401 will sound great yet is not too big to kill it --it runs like a much smaller cam IMO I usually install it at about 105 in a higher compression and around 102 in lower with fantasic results--best street cam ever for CHEAP