[clay68c10]

I've got 101cc heads and flat tops on my 454 and I'm at about 9:1. I can run crap gas thru it if I keep the timing low, but it's WAY more fun to run the good stuff.
I'd guess you would be at about the same compression as me with those heads, maybe 9.2 or so. There's no way to be totally sure without measuring how far down in the hole your pistons are at TDC and doing a CC measurement on the heads.
If they did a good valve job with hardened exhaust seats that is a pretty good price. You may have to swap your valve springs if you've got anything beyond stock valve springs on your heads now. Stock BBC springs are pretty low-lift and don't like aftermarket cams.