SBC
I went far crazier than you on the cam for sure! I learned the hard way as
I have tried any number of SBC combos in my truck. All were short lived!
Spun bearings being the main trouble.The higher in HP you get the shorter
the engine service life in the heavier bodies. I'd either drop the comp ratio
and do turbo or just make the jump on up to BBC.I did the BBC and have
been quite happy with the results! Gas mileage actually rose 1.5mpg! That adds up on a daily worker! I also see by the OD tranny you are trying to get away from the low geared rear end.Good move! I'd be concerned about the tranny strength though. I put a BBC in a friends Suburban we used 353 rear gears and the 400 turbo.He is really happy with the combo and getting around 17 mpg with all the power he could ever use!
The added benefit to me is I'm cutting down that Honey-Do list and playing
with my real toys instead of pulling those pesky SBC's in and out!
Don't get me wrong,SBC is a tough little engine.but you are asking a lot
of it on a daily basis.