Thanks for the replies guys. Yea I don't plan on this thing to do 150 mph but low end torque is what I want/need. I don't know much about aftermarket cams. What's a good lift? Duration?
There is lots of things to think about here first , tire size , gears , what are you going to do with the truck , etc...... but I will just tell you my set up (mean)
77 1/2 ton , 4.56 geared 8 lugs , turbo 400/205 , 38 inch ground hawgs.
407 smallblock
scat crank , cast steel 9-400-3750-5700
5.7 rods
square decked block
forged 22cc d-dished piston's at 0 deck
felpro .039 head gaskets
afr 180 heads , 65cc
eddie intake
comp xe268h cam 224/230 dur at 0.050 ,477/480 lift 110 lsa
crane , springs , locks , retainers , rockers , push rods
cloyes true roller chain
doug thorley headers etc...
My daily driver at the time , never broke down , very fast , won a lot of street truck mud bogs with it , 4 wheeled it all the time , great set up , must have a good 4 row radiator to keep things cool , pump gas.
Save some money , the vortec heads work great for torque , but they dont do well after 4500 rpm or so and you have to watch the lift of your cam.
Figure out your compression you want to run , (quench is the way to go) , then selct your cam to keep the cylinder pressure high , (165ish for iron heads , 185ish for aluminum heads) and you will be on your way.
Yes there is a lot more to it but this should get you started.
That set up I had was 400hp or better all day long and over 400lbs torque at 2000 rpm all day long and I would guess about 475ish at 4500 rpm , crazy fun to drive in a big truck and would run out to 6000 rpm.
hope this helps , I only mess with big blocks now in my square's.