fuel pressure reg : you will only need to change it if you run high boost. thats a dumb sentence cos "high boost" means bugger all. If you run less than 14 psi, there is a chance that the standard one will do the job.

Think about it, a fuel pressure reg is plumbed into the intake. when vacum is present, fuel pressure is lowered. as the vacum disapears, the pressure goes up. so a boosted car will increase the fuel pressure. However, if the diaphram inside the FPG gets "stretched" too much it may burst.

thats my understanding.