Just have a steel driveshaft built and add 1350 joints if your that concerned... and if your gonna do heads then personally I would have the 243's ported and then milled down close to 60cc chambers to keep your compression. You can reach you goal with the stock heads though.

 

15 psi is a lot with no meth or e85. You are going to be pushing it. Leave it stock besides head studs/gaskets/springs/pushrods. Put the money into a GOOD meth kit and top notch tune. Bottom end is fine in stock form.

 

Bingo, if your wanting to play with the heads when there off, get them cleaned up and maybe larger valves, then install your new valve springs. Also if your wanting the engine to live at 600+ on 93, you need to keep a Very good tune, engine temps around 180, and the best intercooler your pocket can handle to keep the AIT low. You have remember you got no room for error/knock or you'll be picking up pieces.

You PM'ed me about Cal-Tracs, I had to cut my brackets and reweld them to get them to work. However those guys sell the modified brackets and everything you need. Just give them a call.