The 3/8" main supports about 230lbs. One cut to fit under each of the Toyota mains for the front shouldn't stiffen the ride at all, especially given the current state of his front leaf springs. I run a 3/8" thick spring under the rear main in both of my 4x4's, to carry the extra weight, and it was only after I added the 2nd 3/8" spring to the '91(sagged too much when loaded w/gear) that it stiffened up the ride enough to notice it when empty.
