There can be big power differences by changing around a few of the variables.......

Engine A-
493” w-std port EZ heads, 10.5cr, Holley SD intake, HP950 carb, 252@.050/.630” lift solid roller cam

Engine B-
493” w-std port SR heads, 11.5cr, M1/4500, 1050 dominator, 277@.050/.660” lift solid roller cam

Engine B made about 75hp more than Engine A, with the same sized/same flowing intake port in the heads(if anything, the heads on Engine A had slightly better intake flow).
Same dyno, same dyno operator, same headers.

There is a HR build here that will be going together shortly where in order for the HP goal to be achieved the lifters will likely need to go solidly over 6K........so we’ll see how that works out.