This may be a dumb question but here goes. I have a 71 GTX that I am putting 15x7 Rallye wheels on with Goodyear Polyglas L60-15 on the rear and G60-15 on the front. My question is with the Rallye wheels. I am having a really hard time finding them and most vendors I have tried can’t really say for certain when they will have them. (I have literally called 15 places and I’m not exaggerating). I have managed to score 2 brand new 15x7’s with 4.25 backspace. I can’t find any more of these but I can find 15x7’s with 4.5 backspace on eBay. A guy has a few new ones from US Wheel. Will there be a noticeable difference if I use these two different backspace wheels? Use a spacer to make up the 1/4”? And which ones should I put on the front or back with respect to the tire size I have. Or.....just wait until I can find 2 more 4.25 backspace ones? Really wanted to have the new shoes on the GTX for car shows this year but if it’s going to look bad or just plain won’t work it will have to wait. Thank you. I always seem to get really good advice on here.

I have 15x7 all around from Specialty Wheels ( now part of Coker ) with 255/60-15 tires on all 4 corners and I never had to worry about the backspace. 15x7" were in fact option, and even 15x8" on certain models

Thank you! Great looking car. I was more concerned with using wheels of different backspacing being noticeable when I am going for a “stock” type look.

Well, I'm not in favor of diff sizes of tires and rims... just a personal opinion. I think will require diff set of rings... Or if still using the same, they will look diff between front and rear. Remember the deal of the trim ring is complete the circle with the reflection

Coker got them if you still are interested on get them set on diff back space for rear and front

https://www.cokertire.com/catalogsearch/result/?q=chrysler+rallye

( editing, sorry, the 4.5 BS is for 15x8 rims. But I think they can go custom )


the reflection making the complete circle effect. With diff BS this effect will look diff between rear and front

without having the wheels in question in front of me, it's "possible" they may have the same back spacing, just measured in a different way.
for example, wheel A has the back spacing measured to the bead seat, while wheel B has the back spacing measured to the wheel's flange edge.
that would pick up roughly 1/4".
both measuring ways have been stated as the "correct" way to measure back space, so who knows ?
it's too bad the wheels are not in front of you to compare.

This is what I was thinking. I do not see where .25" is going to make a difference in drive-ability and performance. I have yet to see a mopar yet that didn't have at least a 1/4 to even almost an inch of side to side variance when you measure rim to fender.

Still, I myself am OCD about rim widths and tire sizes. They can mis-match front to back but not side to side. Maybe that is just me.

The wheels I have (4.25 advertised backspace) are Wheel Vintiques 56-5712044. The wheels that I have found are US Wheel (4.5 advertised backspace) part # 667-5812 if this helps at all.

If it matters to you 71 cars should have brush finish trim rings so the reflection of the wheel holes in the trim ring would be reduced by a decent amount.

You can always buy the 4.5 backspace ones and run them until you find a set of 4.25 wheels and trade them out later?

sounds pausible, but.... the diff on total width between bead seat and outer flange is 1" so it should be .5" difference, not .25"

that is true, however, some companies measure to the inside seat area [thus your 1/2" measurement], some the outside bead seat at the outside of the wheel, and some the flange itself.
it's too bad there is no standard way to measure backspace.
and now, a lot of wheel makers are using positive and negative figures expressed in millimeters. and the dummy i am, i don't understand that way at all !
i'm sure you get the mm way though nacho !

I do have the brushed rings and the dark argent centers. Yes! Going with all 15x7 wheels. Trim ring gap on the 15x8 wheels bugs me just a little.

Sure, my world is in milimeters LOL. Pretty much easier than inches!

In fact all the MKS system and related is way easier by far than imperial measurements.

.......

Brushed rings also reflects the full circle, just blurry.

And yes, the propper trim rings for 8" wheels are hard to come by.

Honestly, I wouldn't overthink the backspace deal, just go with stock 4.25" and done. I think they will look better than 4.5" on a B body which got huge wheel wells. Nice and deep look. I guess if you are looking at 7" wheels with larger backspace, on a frontal view will seems to be a 6" width rim.

I also have a 71 GTX, I put a WANTED post out and got a mint pair of 15x8 Rallye's WITH 275/60 BFG Radial TA/s for $575. I'll be picking them up at Carlisle ina couple weeks. I'll be selling my rear 15 x 6.5's soon if that helps - I'm in MA