Here is my experience -

493"
flat top ross pistons ( .004 in the hole)
eddy rpms 84cc
should be about 11:1
610 lift flat tappet/ 268 dur.
34 degrees total
.039 gasket (Edelbrock)
ran it on 92 pump for a while (all summer racing) .

popped a head gasket---could have been anything , but...
I replaced the gasket and started running 50/50 blend gas , 110 + 92 pump = no problems after that.

hope this helps