Boucher,
Don't forget to zero deck your block,having a tight quench should help prevent/supress detonation.
I know about this first hand when I ran 12.0:1 compression & had 220 to 230 PSI of cranking compression with no detonation on pump 91 octane gas.Daily driver I will add.
I actually have a positive deck of .002-.004.
Stock cam is a bit anemic.
I would run different.
Something like this but on a 115-116 lobe center
Comp cams 61-232-4
C60-252H-10
252 / 252 @ 0.006
0.474 / 0.474
206 /206
110 ,,, no good,, use a wide lobe center camshaft.
The best working of the Chev 6 manifold designs as the fuel mixture breaks up best when hitting the ends of the manifold. On other "sweeping" designs", the #1 and 6 cylinders receive a heavier charge than 2 and 5 for uneven distribution to all the cylinders
This wesite states also why I like the Offy intake
http://www.aaamarine.com/servlet/the-704/5416-discount-Offenhauser-Chev/Detail

That is the reason behind I split my Clifford intake.

Maybe I am thinking incorrect & so are the people of that website? Kinda makes sense to me though.

MBHD

12 port SDS EFI