I did find that art carr makes a flex plate for 50oz in a Mustang ll so I am now weighing my options on a HO swap, The big problem with the 70's 302 is a dish piston that nets 8.4 to 1 compression with stock heads 67 to 70 cc's if you use an early head52 to 54 cc non erg you can get almost 10 to 1, Most aftermarket heads are in aluminum are 64 cc's
been their & done that you can get 58cc heads in aftermarket & oe heads just dont flow