I have the 16-6-50 8 tires on the front, and would like to replace with the 480-8 tri-ribs. I've seen a photo of the tri-ribs on my current rims and I'm not a fan. What size rim am I looking for and where would I find it? I don't even have it running yet, but the front tires are so rotted they won't hold air, so it will it least make it look better while I am pushing it around my garage.