Buy a shim kit. What this is, is a thick plate that goes on the bottom of your cylinders and a machined head. You install this and you don't have to do anything else.[no jetting] What it does is changes your port timing to give more hp and does not change compression therefore not hurting the motor. Go to www.sledpro.com I think they sell them.
p.s. watch for crank bearings on the 780 they've been known to go.