I can help on the 6.5 pv. Thats the power valve. it opens when the vacuum in the engine goes below 6.5 inches of vacumm. When it opens it provides more fuel to the engine. The size is determined by your vacumm reading at idle. You divide your idle vacuum in half and that is generally the pv you should use.

best of 11.24 at 119 mph 1.60 60’. 68 340 S Barracuda Fastback F.A.S.T [IMG]http://i67.tinypic.com/2mnnnnt.jpg[/IMG]