front wheel size for 1968 Dart

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John DePauw

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I have a 1968 Dart what size 15 rim will work on the front is a 15x7 too wide and what back spacing is best.
 
A 15x7 is fine, it's really about the widest front rim that's worthwhile with 15's. Backspacing depends on your braking set up, if you've converted to BBP then 4.25" of backspace usually works well with up to a 225/60/15 tire. Too much more backspace than that with a 15" rim can cause interference with brake and suspension parts. Less backspacing than that will limit your tire size because of fender clearance.
 
Yes I have converted to BBP

So going BBP with OEM parts widens the front track, I've seen it some where around 3/8" per side. I run a 17x7 with a 19mm offset (4.75 back spacing) and it worked with both OEM and Dr. Diff 13" brakes (with pushed them out another 1/8" per side). But, like 72bluNblu said, you move it too far and you hit the upper at arm with a 14" and 15" wheel. So a 15x7 that has a 4.25 or 4.5 back spacing is ideal but, as I found out are not overly common (especially in 4.5" back spacing) if you want something less mainstream (i.e. Rallye, Steel, Cop, Magnum 500, Cragars, etc) which is why I went 17" custom wheels and got a far better street tire selection at the same or less than 15".

Then there is wheel hub size.
 
So going BBP with OEM parts widens the front track, I've seen it some where around 3/8" per side. I run a 17x7 with a 19mm offset (4.75 back spacing) and it worked with both OEM and Dr. Diff 13" brakes (with pushed them out another 1/8" per side). But, like 72bluNblu said, you move it too far and you hit the upper at arm with a 14" and 15" wheel. So a 15x7 that has a 4.25 or 4.5 back spacing is ideal but, as I found out are not overly common (especially in 4.5" back spacing) if you want something less mainstream (i.e. Rallye, Steel, Cop, Magnum 500, Cragars, etc) which is why I went 17" custom wheels and got a far better street tire selection at the same or less than 15".

Then there is wheel hub size.
I want to use the Mopar Rally wheels(Rims) 15x7 rear with a 4.75 backspacing and I just wanted to know if a 15x7 on the front would clear as right now there is no engine or suspension on vehicle, I converted the rear to disc so I have to use at least a 15 inch rim and I installed the Mopar rear spring hangers that move the springs in about 1/2 to 3/4 US Wheel said they can make the rears with a 4.75 backspacing.
 
Are you sure on the 4.75 back spacing? What disc kit and axles did you use on the rear?
 
Are you sure on the 4.75 back spacing? What disc kit and axles did you use on the rear?
I used the MBM disk brake kit # DBK834LXR From Mancini Racing. I mounted a friend 15x7 with 4.25 backspacing and a little to close to fender lip had plenty of room in rear to go 4.75. The axles are stock Chrysler that were shortened and re splined that have the 5 on 4.5 bolt pattern.
 
I have 15x8 with 4.5 backspace and 225/50/15 on the front.
Need some info on the MBM rear disc brake kit that I put on the rear of my Dart. will the factory brake cables work with this kit as I don't like the way the cables that came with the kit route.
 
You didn't say if you had shortened the axle housing, but you shortened the axles? Stock housing will take 15x8 and 4.5 backspace. 255/60x15 tires. With a 4.75 backspace, you might get 275's in there, I think they would fit my '69 anyway.
I have more room on the inside than outside with 255's and a 4.5 backset.
 
You didn't say if you had shortened the axle housing, but you shortened the axles? Stock housing will take 15x8 and 4.5 backspace. 255/60x15 tires. With a 4.75 backspace, you might get 275's in there, I think they would fit my '69 anyway.
I have more room on the inside than outside with 255's and a 4.5 backset.
What rims do you have. I put a disc brake setup on rear so I need a rim with a minimum of 13 inches on the narrowest part of the rim to clear the caliper, also with the disc setup it moves the wheel mounting out about 3/8 of a inch on each side so that changes how much back spacing I need.
 
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