The wheel will weigh more, the tire will weigh less.

IMO Bill's braking theory is correct, but in reality it has been my experience that it is not an issue.

While I agree that there will be a weight difference I've updated numerous vehicles in my life and have yet to ever have any braking issue when updating tires and wheels.

This is especially true on a pickup truck that has over sized brakes, sized for carrying payloads.

Case in point, my '65 C10 had stock brakes, yet the rolling stock was altered. No adverse handling or braking issues. http://i645.photobucket.com/albums/...Trim%2001-24-2015/RR3-42_zps5434b9dd.jpg

FWIW: In regard to putting 20" wheels, specifically 5 spoke Boss 338's, on a stock braked, 60-66 truck: They look horrible. A 15" 5 spoke wheel looks good, but the 20's are to big, they make the stock brake drums look tiny.

In the Stovebolt Gallery ~~ "The Orange Crate" 1965 C10 SWB Step Side Build Thread

Inspired to be different. Different in a way of my own, not in a way that others strive.