[rbar]

I didn't see if you stated whether you had dished pistons or flat tops.
If you have a deck clearance of .025", a .039" head gasket, 6cc flat tops, and 64cc heads, you should end up with 9.6:1 compression on a standard 4" 350. I have read that the 64cc camel humps actually cc out to 68. If that's true it will drop it to 9.2:1. I've had 3 pair but never checked it. I'll be checking some off a 327 next week.
If you have dished pistons, it will lower the compression more. I seem to recall 12.5cc as being a common 70's dish cc. at 12.5cc and 64cc heads, the compression would be 9.03:1. If your deck height is more like .040" instead of .025", it drops it another .25 or .3 in either set up.
If you don't have bolt holes, which I don't think you do on 1965 heads, take a look at the alternator and power steering brackets from Alan Groves that don't use head bolt holes.