The key is a tool called the Gryp-R. It's a fixture that bolts onto the hub of your ride and holds nearly any tire in place so that you can check the fitment before you spend your hard-earned cash on the wrong set of wheels and tires. It's easy to use and as you'll see in this video you can get all the critical measurements done in a matter of minutes.
I ended up stuffing the widest tires I've ever seen on the front of a lowered Chevy C10; I ordered a set of 295/30ZR20 Michelin Pilot Sport 4S tires from Summit Racing and then had Forgeline build a set of GA3R wheels in 20x10.5 size with 4-inches of backspacing. The wheels have Forgeline's optional "open lug" design and are extremely light.
You can find the tires here:
And the You can check out the wheels here:
For more information and a DISCOUNT on this tool or Scott Blair's mobile tire installation service visit this link: http://www.thewheelfit.com/fsm.html