I am looking to buy some new wheels. I am looking at these Gear Alloy Backcountry wheels (see pics). I know nothing about wheels. What kind of dimension information do I need? I know they are 8 lug (duh), but offset, backspacing, all that I do not understand. What do I need?

 

well you need 8x170mm bolt pattern and thats about all i can tell you. Subscribing because i would like to know the same stuff

 

Trey, are you looking at the 18" or the 20"? The 719MB is available in both, and both are 9"wide. Your OEM wheels are only 7" wide.

You need 8x170mm as noted above.

Offset is the distance from the mounting face to the centerline of the wheel. Your stock OEM wheel has a .25" offset, meaning it mounts almost on the centerline. An offset spec should include a "+" or "-" for positive or negative, but the Ford spec doesn't mention which it is. But at only 1/4", it isn't of much matter.

Backspace is the distance from the mounting face to the inside bead flange. Those Gear wheels have a 5" backspace and a 0" offset. You can pull a wheel and do some measuring on your truck to see if the will clear. I think they are meant for the early SD like yours, because that is far too much backspace for the '05 and up SD. But of course it depends on the tire you mount.

I would call them and ask. I'm sure they get asked that same question every day. Also ask them the weight rating. Their specs leave a lot to be desired for information.

Edit: I found this spec page.
719MB
It notes which models fit the "older" trucks.

 

This link might help:

Wheel Offsets - Discount Tire

 

Depending on what size tire you want to go with you can probably find a good set of factory 05 up FX4 wheels. They are 18x8. But the biggest recommended width you can go with is a 295 on an 8" wheel. That's why I went with the Nittos, only one of 2 tires you can get in a 295/70/18. They are 34.5" tall which is as big as I wan't to go with anyway because I pull a camper. But anything over a 295 it's recommended from most manufactures to at least have a 9" wheel. I didn't want aftermarket wheels because I like the factory center caps as goofy as that is. So the widest I could go was a 295. When the wheels get ugly I'll prob go with a 10" wheel so I can go to a 315 width. As BP mentioned make sure the weight rating is up to par. He is absolutely right about that in my opinion. Big truck + E Range tires + wimpy wheels = dumbness.