Heads issue
If you are planning on seriously running 100 LL av gas dont worry about the CR. You wont have a problem up to anything around 13 :1, Buddy of mine ran a ford 390 with this kind of CR and 100 LL and never had any issues with detonation.
For the heads. If they are in good enough shape why not finish whatever porting needs to be done, throw in 2.02 and stainless 1.60's and call it a day ?