Originally Posted by
matt5112
CC's are both 64 cc.
The only difference in the bottom end are the rods, pistons, pins, balancer, flexplate, and cam gear.
You cannot check compression ratio short of boroscoping both types of blocks or CC'ing the pistons.
The cam gear in a N/A block is 1* advanced. Not exactly detectable.
Compression test values are quite a useless figure considering ring wear and valve/seat wear would negate any differences.
Closing the gap isn't the best way to solve this.
Have a known good ICM you can swap in?
When I first top swapped my car wouldnt run KR free past 2 psi until I swapped out the ICM for another unit.