DodgeCoronet.com

Pretty basic question, but I haven't needed to do this in the 50 odd years I've been messing around with cars. My '66 '500 currently (318 Poly, 8 3/4 rear end) has 14" "Road Wheels" on it & they look great. However, what I REALLY want is a set of 15" Magnum 500's, just like the ones that were on my '68 GTX. Priced them out at Summit & we're planning a road trip to Ohio in the Spring to pick up a set. I'm a bit confused about the proper way to measure the dimension from the rear of the bolt surface to the rim (back space?), also the diameter of the bolt circle. Placing a straight edge across the rim at the outside surface of the tire bead, I come up with about 3 3/4". Measuring across the bolt holes, mid point to mid point and skipping one hole, I come up with 4 1/4". Am I doing it correctly? These numbers seem "close" to what I've read but not exactly the same.

Help!

It will be 4 1/2 , outside to center of same holes you measured.

Back spacing is from edge of wheel to bolt surface

X2 on the 4.5" bolt pattern

how to measure back spacing-

http://www.summitracing.com/expertadvice...ackspacing

The Magnum wheel can fit Furd and Mopar.... so the center bore is also critical. Here is a great simple diagram with everything you need.

Just what I needed, boys. You guys are the best!

I can tell you from experience ,money wise,what the biggest tire will fit in the rear,why does it cost so much money when you screw up?