Hey Mark, In regards to your tire pressure. Its all about weight, and tire size. With the added weight of the V8, automatic transmission, and I’m guessing 16580R/15 tires. Up front about 32 to 35psi, and maybe 30 to 32 psi in the rear. If the tires are wearing excessive in the middle of the tread, you will want to lower the pressure, only about 5psi. This should get you rather close to what you want for a good ride, and traction.