77 T/A 403 Heads

Backround for the T/A 6.6 engine pontiac just took it's regular 350 heads and bolted them onto the Pontiac 400 engine with slightly more agressive cams. This boosted compression ration from ~ 7.6:1 to 8.1:1

I'm want to Bolt on an Edelbrock 3711 Intake Manifold (only one that allows shaker scoop to clear hood) and I'm considering, since there are no aftermarket heads that do the job, to score a set of preferably rebiult Oldsmobile 350 heads and bolt those on. The thing is, the Olds 403 had a stock Compression Ratio of 8.0:1.

so here are my questions:

1)Should I keep the current heads and rebuild em with performance parts? and just go for cams and such?
2)Are there any special considerations I need to be aware of?
2)What compressoin ration can I expect?
3)What Octane should I run for that compression ratio?

See my response in the "Olds" section...

Thanks, wasnt sure where best to post the question.