Sounds to me as if you are going for the Calif raked look with your truck? Like we setup our cars in the '60s. We raked them with rubber. Some of the more well heeled guys cut the front springs to get low in the front. I setup my 55 2nd truck with 15in wheels all around, keeping the 6 lug mounting. It came with 4 American Outlaw ll wheels when I bought it. They were 10in wide. The PO had put 225x60 tires all around, they were almost 9in wide and the truck steered like a mule with two broken front legs! I replaced the two front wheels with 7 in wide rims and mounted 185x65 tires. I put 235x75 on the 10in rims on back. Truck steers ok now, and the big meats, on back, give a little more top speed and lower rpm. I think the truck has a nice rake look to it with out dragging the ground when going in and out of Dairy Queen.... And if I ever get a flat, it will be easy to jack up. Your setup may be different, but there are alot of factors to consider.
