Those tires are going to look great under there.

"........4 inch mini-tubs in the bed so the bed is even with the frame rails so I can fit these 295/50/15s on 10 inch wheels under the truck....."

Yeah , I had to go look under the back end of mine. That would be a fairly easy job to pick up a bunch of tire clearance. work

Those brakes should be plenty for the truck.

1957 Plymouth (Hemi, Dual Quads, A833 4 Speed 9 1/4 w 4.10) Sold
1937 Dodge Pickup (Hemi, 6X2 intake, 46RH, Dana 60 w 4.56) Sold
1968 Plymouth Valiant 2dr sedan (354 HEMI, 46RH w/4.30 gears)