I searched here and on google and I can't find what I'm looking for. I need to know the stock offset and backspacing for my truck and an 81 Ram. I've got an 89, and somebody with a 1981 dodge ram wants to trade me tires and rims and I need to see if his will fit. They are both 5 x 5.5 bolt pattern, but I don't know the offset and backspacing for either vehicle!!

I have aftermarket wheels and they stick out a bit, he has a set of 81 ram stock steel wheels with 31 inch tires on them. I would have to drive a ways to meet him, so I'm trying to guarantee a fit before I drive way out to swap. Anybody know the backspacing and offset I need to prevent rubbing??

 

isnt offset and backspacing the same? Stock rims are 3.75'' backspacing.

 

Offset and backspacing are similar but not the same. I think backspace is more important for me than offset. If I understand it right, backspace is the distance between where the hub bolts to the rim at its mounting surface and the innermost lip of the rim. If there isn't enough backspace I'm going to rub on my radius arms and frame and whatnot. The smaller the number for backspacing, the more room I actually have back there.
Offset is measured from the center of the rim to the mounting surface of the rim (negative offset = deep dish rims).

If stock f150 backspace is 3.75 inches, and the stock rim width is 8 inches, then the offset would be -19.

I just don't want to rub on my radius arms. I have a 4 inch suspension lift which negates rubbing the fenders, but I like the stance my truck has with the wheels sticking out a bit and don't want any rubbing. Has anyone ran ram wheels on their truck?

 

most stock truck wheels have the same or close to the same back spacing
if you like the way your tires and wheels look now then i would just stick to them,

 

I like the way they look but not the way they ride :p I have 33" mud tires, I'm looking to bump down to a 31" all-terrain. This guy has brand new 31" falkens on stock wheels he wants to trade. He's selling his truck and thinks the 33's will make his sell better. I wish they were on the stock ford bullet hole rims but if these tires are as new and good as he says its a good deal.

 

http://www.discounttiredirect.com/di...yp=Truck%2FSUV

buy a set of these if you dont like how the mud tires run, they are falken too!!!

but your going to look like the truck is going to tip over you stick 31's under a lifted truck

 

I wish I could, but new tires are out of the picture right now. Plus I'd like to go down in size a little to help my gas mileage as well. 31 is as small as I want to go. It won't look too bad on the truck, and I can still run it on a stock width wheel and help the 2.47 gears out a bit.

 

Stock rims are 7.5 not 8.

 

Well I didn't wind up with those 31's anyhow, my 33's wouldn't clear his truck width wise, they rubbed on the back of his fender. I went to the junkyard yesterday and couldn't find a good set of stock rims or tires either. The search continues!