302 heads

I have a pair of 302's on my 360ci. 11.3:1cr
Measured 234 rearwheel HP, powered through a 518 transmission on propane fuel.

I have a pair of Streetmaster heads coming my way.
Will be very curious to see what they achieve on the same engine and see how 'corky' the 302s are. Also plan to mill the alum. heads to end up with the same CR.