...5+8.8+62 that is a total of 78.1cc. At 4.03 bore, that makes a swept of 748.3------- and so (748.3 +78.1)/78.1=10.58 scr.
A cam with an ICA of 68* makes 165psi@137VP, pretty well on the edge for iron heads and pump gas at sealevel.
At 900ft and 70*, you are down at 157psi@128VP.
The Q would...