BB cylinder head question

I have a 67 Formula S fastback 383 auto. I'm pulling the motor out to freshin things up and check out what needs replaced. The motor was rebuilt in 98 and is supposed to have around 5000 on the rebuild. The car definitely needs a transmission rebuild and the stall is utterly shot. Im pretty sure they didnt use the correct 10:1 pistons but I won't know that til I do a compression test. My question is what is the difference in the big block heads of 68 and 69 compared to 67. I know the 67 heads are a non quench type. Would it be benifical to replace the 67 head with a later 906 head?