Wheels following disc brake conversion

[S_Bruce]

Hey guys,
I recently replaced my front drums on my 1970 Challenger with a disc brake conversion.  I used the Stainless Steel Brake Company's conversion kit, which went on in a breeze and without a hitch.  The only problem is that now, the wheels I was using on it do not fit properly, they rub the calipers.
The wheels themselves were some used, no-name brand aluminum jobbers, 15x7 with 4" of backspace.  I have a set of rough Magnum 500's (14x7) that seem to fit without rubbing, with about the same backspace.
So, my real question is, who is running their car after a disc brake conversion, and what kind of wheels are you running?  I'm tired of putting used wheels on my project car, and am ready to break down and spring for a set of new wheels and tires.  I do not, however, want to blow my money on cool looking wheels that don't work with my modification.  The other problem I'm running into is that the car is not running right now (engine swap and re-wiring the whole thing), so I can't take it to a tire place to get it fitted.
Thanks in advance for any help!
Steve

[422STROKER]

Check this thread many combos in there.

Tom


http://www.cuda-challenger.com/cc/index.php?topic=19470.0

[S_Bruce]

Thanks, there is a lot of good info in there.
I guess what I'm wondering is, why would two different sets of wheels with the same backspacing fit differently?  One set hits my calipers and one does not.  I was looking to see if anyone else had performed a disc brake conversion, and if so, what wheels/tires are they using on their "not-stock" car?
I was really hoping for someone to say "Oh, yeah, I did a disc conversion and use a (insert wheel type and backspace info here), and don't have any problems."

[ChallengerHK]

Thanks, there is a lot of good info in there.
I guess what I'm wondering is, why would two different sets of wheels with the same backspacing fit differently? 

Backspacing is only part of that equation. One of the other parts will be the shape of the inside of the wheel as it curves from the mounting pad to meet the rim. Some wheels will have less clearance here than others.

[Aussie Challenger]

     ChallengerHK is right, but also I have found that sometimes it is only a wheel weight placed in the wrong spot that hits the caliper.   

[HP2]

Many moons ago when muscle cars were new, most of them came with drum brakes, so most wheel manufacturers built wheels that fit them. It was until after 73 when discs began to proliferate that it became evident that the wheel manufacturers would need to retool to fit more wheels on more cars. So there was a period when wheels could be purchased as non-disc or disc applications.

[S_Bruce]

Now that you mention it, the Magnum 500's do sort of "arch" outward then back in.  I guess I'll have to pay closer attention to the shape of the wheel, not just the proper backspacing.  BTW, that link posted in this thread had great info on BS and tire size, so thanks again!