I just bought a 1950 Suburban, don't even have it home yet but it needs new tires. I think 6:40-15 is the correct size but can anyone verify that? Would I gain anything by going to the next size up, 6:70-15? Its only going to be used as a Sunday driver. Thanks! And oh, Jim B: my Powell hasn't move in years but at least it will now have a garage mate with the same family lineage!
the larger diameter will give you a higher rear gear ratio, so you will save a few RPM's at speed. Also make sure you have enough space in the wheel well.