Assuming you are running zero deck flattops ( like I am) you will be nowhere near 12.6 compression.
I had Rod mill my heads to 61cc specifically to get my compression up around 12.3-12.4. At 70cc it would be under 11.5.
Regards cam, know a couple guys running the Crower roller(268/274) with great success with Bloomers. Dont think there would be a need with a glide and relatively heavy car to go much if any bigger.
It’s the cam I would probably buy if I upgraded to a roller.