Ok so .050 gives you 11 cc without the quench pad add another cc max for the small quech and the two other very small quench areas. thats 12 cc out of a 112 cc head. Even if they were closed chambers it would take them to around 88 cc.
Now that is still well short of the goal if my math is correct please verify for me. Let me know if i am wrong on this one.
Pontiacs dont make good power with low compression. And stock heads including these have 153cc intake runners.
Smog Head Performance - Tech Articles - High Performance Pontiac Magazine