Even though those heads are listed at 72 CC, I would measure the chambers anyway. They could have been cut too reduce the volume. If they were mine I'd be inclined to have them cut to 60 CC. AFR lists those heads in that size to or at least Summit does. I agree, I feel leaving them at 72 is going to put your CR in the low 8's.
It'll still run well, after all it's a air pump. The more air and fuel you move through it, the more power you'll make. Just that you'll be leaving a little bit of power on the table.
I'm not a complete idiot, pieces are missing.
Last edited by Huskinhano; 03-16-2017 at 09:24 AM.