Custom cal/head compatibility

[The S is Silent]

How is a cal different between a 287 head and a 782 head? What would the difference be if I ran a cal designed for the 782 head on a highly ported G-head?

[turbovanman²]

The g-head needs more spark advance due to the lower comp ratio. It could run a bit lean but you can always watch your guages and turn up the fuel presure if needed. I would give it a few more degrees base timing and go play. If its quiet, give it some more until it pings or using a scanner, see knock.

[cordes]

You would probably want to adjust the pumpeff table too since the head will be ported.