I have both and have read them. the how to modify book does not even talk about later the later P79 but a lot of nice to dos for sure.
The Mod seems pretty straightforward, shave the head .080, shim up the towers and outer springs 0.80 inner .40, install shorter valves, pick a performance cam, springs and retainer, figure out the geometry for the lash pads and run with it. End up with an updated head with higher compression which seems logical for a performance engine!?