high comp will start better in cold weather.
but not much power.

high boost will be more power, but reliability becomes an issue.

 

Ya I would like to run around 16 psi with the stock 21.5 comp. You think its possible by any chance?

 

With head studs and some good gaskets you could do 16psi on occasion. I still wouldn't go trying to peg the boost guage every chance you get. You would need an intercooler as well, no point in having more than 10psi without one.

 

like he said. i am still thinking about fireringing mine just in case. never seen a fireringed 6.9

 

The firering job would be a good idea to.

 

Ya trust me I'm going all out, New pistons new valves port and polshied heads, new lifters,cam,splayed main caps. Glyptal lifter valley, two intercoolers one for turbo, one for block with five tank radiator. Fire ringed arp studs head and main studs. And the rest of the goodies