In Frank McGurk's day a 235 head was a good way of upping the ratio --dunno if that was based on advertised ratios or if the were actually cc'd--he said it was better than milling because of having to sink the intake valve and shortening the intake stems when milling the 216/261 heads (261s were like 7:1 and pass. heads were like 7.5 up to maybe 8.25 around '57)--what made the diff?--now we're talking here of pre 1955 stuff when cc-ing wasnt a national pastime.
I had a '54 pass. 235 head on a '59 .060 over 261, and a '56 pickup 235 head on '62 .060 over 261. Both didnt like cheap gas- the latter had a TRW 270/280ish cam, and the former a stock 261 cam. The stock cammer was in a 6 volt '54 chevy and was a hard start in the summertime, the trw cam motor was in a 12 volt '56 pickup always easy to crank. Sorry to add to the confusion.
