That should work fine...comp.ratio will depend on deck height, gasket, few other variables, but 10/1 is a ballpark number with those .280 domes. Flame travel is always an issue with a domed piston, anything that is in the way of the flame travel will mess it up a little, but it's not anything that you will notice or feel. Im not a big fan of Edelbrock cams, but that one should work good with your combo.....Im sure with those specs, it will need at least a 10/1 C/R. Is it an automatic or standard...if auto, what stall converter?? 781's are great heads too, dont get rid of them.