[Trackrash]

I would hold off on those pistons and cylinders, until you have totally disassembled your motor. Chances are you could re-use your cylinders and just buy some JE 9.5 pistons.

10.5 to one would require twin plugs. That is a nice option IF you have the budget for the ignition upgrade $$$.

My main concern, if I was you, would be the condition of the case. 2,7s are known to have problems with those mag cases and can require some expensive work to get back in spec.

What cams are those? DC 30s? That would be a good choice, depending on your other mods, especially the compression ratio you want to run.

Does your budget include the Webers? Do you have those already?

36mm for the intake ports is probably what you want.

If I was in your position, I would look at the possibility of boring your cylinders, if they need it, and building a 2,8 or 2,9.

Do you have Waynes book, "How to rebuild 911 Motors..?