I reckon the heads will be good for well over 700 bhp + with the right spec.

The head was developed by the Special Vehicle Team in the USA.

The cosworth equivelant in the States

A ported Cosworth head with standard valves will flow 158 CFM

A ported ST170 head with standard valves will flow 183 CFM

You do the maths

They are by far a beter designed head,

No one seems to have cottoned onto this yet though apart from me and a few others



Already bought a ST170 head for the next upgrade