Originally Posted by XRT_si
Ian Howell told me the ST170 heads flow 400 pretty easily but needs the exhaust ports taken out a bit to go any further? Also mentioned i need a cam (or cams cant remember) and uprated valve springs.
However Iam hoping whats been said here is right - Standard Cams, valve springs and ports all capable of 400 as of standard?
me to mate ian told me the same
