Head port and a serdi valve job matched to a cam with a nice exhaust, add a dash of compression and serve hot. voila. 

+1 old style hotcams are pretty nice, and I would recommend the full Yoshi pipe.
But really you don't need to get it ported just get in that 12. compression reange (13+ will require race fuel), some old style hot cams (new style are fine just OSHC seem to be better), full exhaust, and a 434 kit. I cant really give insight on which one but Im pretty sure I see good results out of both of them!
Also don't be surprised if your threads are stripped on the cam journal cap(s) its very common in these machines.