exhaust, go for an OMP systemthey are ace!!
as for the PBV.........nothing, waste of money......
if you really want to increase the base line fuel pressure, why dont you just get an adjustable fuel pressure regulator?
itll be 50% cheaper and do the same thing, if you campare the 2...they will look almost exactly the same!
What it does is just add more fueling every where.......which make the engine run rougher if its not drawing in more air to compansate for the increase in fuel. it should be the other way around.....fueling is the EASY part, getting the angine to process more air is the harder part......so, i personally wouldnt even bother with a PBV.
but you will get arguements from people saying it works, im not disputing that with some mods, a PBV (fuel pressure regulator) will just adjust fueling (in a very very crude way) go to nick hill if youi have any mods and want fueling adjusted sa the std fuel pump and regulator/return valve will be able to cope NO PROBLEMS!
Ben