Egon, I've had 4 inch exhaust on it since I first started in on it before it was a year old and a large free flowing muffler that is a bit louder.

Weight in the bed???? Don't you think the service body, contents of the cabinets, and the 65 gal fuel tank are enough? Basically weight alone is not a winner as the same weight that provides traction provides inertia to retard acceleration. Better weight distribution and weight reduction provide better acceleration.

Pat