First 318 build, cam question

I ran that cam in a 318 I bought. It was supposed to be a 9.5:1 motor with '75 360 heads. Turned out to be a 7.5:1 motor, did have '75 360 heads that I did a minor gasket match and bowl work to, an eddy air-gap intake, holley 3310, locked out dist, in a 3650 lb duster (me included) and 3.91s. It ran ok, never tuned it and ran 14.70 at 92ish MPH the only day I took it to the track. Idled at like 700 rpm and knocked down I think 18+ mpg. really wish I would have thrown the nitrous kit on that motor