there's certainly no need to reinforce the frame unless you intend on a lot of clutch popping drag racing with a really built engine, the added torque of a "usual" 350 over the original era 283 isn't huge .... what rear ratio you want depends entirely on what you're going to use the truck for, work, pleasure or showing off .... a 3.55 ratio is available for the stock rear and works fine for good mileage on the highway without losing a lot on the low end, an overdrive trans will do as well with the stock 3.90 rear
Bill
