Originally Posted by
crazycage
you will deffo need the uprated valve springs i got mine from ian howell,and theres no point putting a good piston on a standard rod .
you can get a rod piston combo from the usa for about £600
i run focus wrc rods in mine .
p.s you dont want to bore it out to 2.1 theres no need
How much were your springs? As Ian Hwoell has told me ST170 heads use odd sized springs so normal ones he does cant go in and must get special sized springs/hats which cost £270.
Iam going for Piper ST170 uprated springs now I think, only £150 and direct replacement.