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This might be my first post here.  Have lurked for a bit.

I'm working on ordering some new wheels for my stock '72 through Forgeline.  

I've attached my measurements / Forgeline fitment sheet.

Love the fitment of Marty Quadland's Pantera.  He went 18" x 12.5" rear and 18" x 9" front but neither he or Forgeline could remember the offsets (was before Forgeline started tracking past measurements).

Forgeline did have specs from a set of wheels they did that had a similar setup to Marty's:

18" x 9" (5" Backspace) / 18" x 12.5" (7" Backspace).

Questions for y'all:

1. Do my measurements look similar to what you all have found (on similar stock Pre L types)? 

2.  If my measurements are good/correct, a 7" backspace on a 12.5" wheel (13.5" rim edge to rim edge), leaves 6.5" frontspace.  This would stick out 1" even before tire allowance (if you reference my rear 5.5" front spacing measurement.  Either the example that Forgeline offered was different/modified in some way or my measurements are off or too ************ or....?

Thanks in advance!


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  • Forgeline Fitment
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The link says Marty's wheels were 18" x 8" and 18" x 12", which I think is a bit more realistic. Fronts will still rub on the inner fender at full lock and I think any more than 6" backspace on the rear and you risk clearance issues, although that may not be as big a concern at 18" dia. Personally I'd go 17" front and 18" rear to ad some visual rake.

If you jack the hub into normal ride height position and measure from the mounting face of the hub in conjunction with a level on the fender lip you should get close on determining the front spacing

Joules is correct; Marty's wheels are 18" x 8" and 18" x 12". I have a stock bodied Pantera with 17" x 9" and 18" x 12-1/2" HRE's. If I were doing it all over again, I'd use 17" x 8" or 17" x 8.5" in the front, rather than 17" x 9". That would make the fronts less likely to rub and would give me the option of running a 245/40-17 or a 235/40-17. A 9" wide wheel is really too wide for a 235 width tire. At the rear I'd use an 18" x 12". A 335 width tire looks better on a 12" wide wheel and it would be a bit less likely to rub the upper frame rail. My wheels are 21mm offset in the front and 16mm offset in the rear. I'd use these same offsets with the wheel sizes I suggested.

My tires are 245/40-17 and 335/30-18 BFG Rival S 1.5 from The Tire Rack.



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  • IMG_1310
Last edited by davidnunn

First off, thank you all for jumping in on this thread.  I live in Colorado but the car is being working on in So. Cal. before we move it here.  I just flew out a couple weeks ago to take all the measurements and I did so with the car resting on it's own weight so that the suspension was compressed close (ish) to where it will eventually be (if not a tad high as I'm adding an adjustable coil over setup).

Really appreciate the help as I can't just hop back and forth from CO to CA to get a quick measurement.  When I was there I really belabored each measurement.

@joules I'm not sure the dimensions are correct on Forgeline's website as 1. Marty told me himself the dimensions of his wheels (didn't know offset) and 2. Forgeline said that they couldn't dig up the past record of the build and so I think the website specs listed is a "best guess".  I could be wrong on that and Marty could have mis-remembered.  Either way, I love the look!

Also, if you see my measurement sheet, I also prefer 17" in the front with 18" in the rear (at least in theory). 

@albanygt40 I would if Forgeline or Marty could get me the full/correct measurements!

@davidnunn See my reply to @joules regarding Marty's dimensions. Your setup looks awesome! Thanks so much for sharing your measurements.  I'll go back this eve and have a proper think on this.  You wouldn't happen to have a few more pics showing a more extreme angle that better shows the wheel/tire inset from the fenders would ya?

Thank you all for your input!

Just went through all the options with my rep at Forgeline based on my measurements and other comps.  Super impressed with the time they take with you in getting things right.

Looks like I'll be going with:


Rear: 18" x 12"  (7.5" Backspace)

Front: 17" x 8.5" (5.5" Backspace)


Continental Extreme Contact Sport

Rear: 335/30  R18

Front: 245/40 R17

Wheel Make & Model: Forgeline GZ3


Center: Silver Powdercoat

Rim: Polished with Clear Powdercoat

Hardware: Hidden

Center Cap: Custom Engraved De Tomaso Logo

Last edited by Blayne Chastain

My wheels were on the car when I bought it 11 years ago. The center caps are not the issue, the hub size is. The center bore for the hub was machined at ~2.638", 67mm. The hubs on the car measure ~2.425", 61.6mm. Without concentric rings they are lug-centric. I know! I'll start a thread with a few pictures.

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