an m62 on a 4.0? they better be driving the "F" out of it to get it to push anything on a 4.0. and in that case its going to eat bearings pretty quickly.
if i was to go super:
blueprinted 4.0 SOHC and balanced rotating assembly, i'd get hte old rods shot peened and stress relieved topped with 8.5:1CR pistons with total seal rings, make sure the heads are straight and clean with some stainless valves, i'd also have the block o-ringed for better head gasket sealing and life. of cousre you'd need a custom manifold, be smart about it and integrate an air/water intercooler, i'd make it so i could use the m112 since it wouldnt have to spin nearly as fast to make power thereby prolonging its life. higher flow fuel pump, bigger injectors, upgraded intake system. of course you'd have to have it all custom tuned.
personally i'd only be looking for 8 psi, but i'd make it so its expandable and i wouldnt have to do it all over agin for a few more psi. the best thing about over kill is extra life.
