Charlie, thanks for that but just spoke to PWR here, Think they are equivalent to your Fluidyne as the place to go for performance coolers. but still could not give oil flow charts, said too many factors to consider, seems trial & error is only way.

Was advised never to use a stacked plate cooler ( which they also sell) in a rotary, only a matter of time to failure. said stacked plate is much more efficient but they have seen too many fail in rotaries.

AUD600 inc freight for their RX7 replacement so a bit better than an import. but they make them identical config in dual pass but with larger tubes. So now I don't know if to try one as is or order one as single pass to get even lower pressure drop... decisions.

Todd. my oil lines are 5/8.

Why pull the safety valve? unless its opening below about 150 psi I'd leave it alone, not much weight to be saved there.