what vendor sells a .520 boost valve

[boostjunkie]

Thanks Shawn.

 

[77 cruiser]

PTS has a .57

Jim

 

[jakeshoe]

Any of the gurus want to comment on how much difference performance wise a .500 valve is compared to the PTS .570?

Since the .500's are dime a dozen now as well as the bigger commercially available reverse boost valve, is there a large difference in the .570 or is it only minor.

Basically what are the real advantages?