Adjustable Proportioning Valve Help
 

Where can i get the adapters to put a adjustable Proportioning valve ( 1/8 NPT )
to the stock Brake line ( bubble flare ) ?
What size are the stock brake fittings ?

adaptors in brakes systems are a bad idea - i would change the proportioning valve to one that has the ratings you want - porsche makes several - one of these might work:

5/18bar 951 355 305 01
5/33bar 928 355 305 01
5/45bar 964 355 305 00
5/55bar 930 355 305 01
5/60bar 965 355 305 01

Not if you want adjustability on a Racecar

it seems to work fine for everybody i know racing these cars - most of them have gone to either the 5/33 (or 5/45 if they really wanted aggressive rear braking) - i am running the 5/33 and am very happy with the balance - fit right into the oem location - no muss no fuss - no real chances of leaks

have you tried porsche motorsport?

What about if you run Big Reds on the front ?