67' GTO, housing narrowed 1.5", wheel and tire fitment question.

[Nicks67GTO]

Im about to order my Moser 9" for my 67' GTO. It has a stock wheel wells and has no mods at all. Ive had a recomendation to order the housing 3/4" narrower than stock on both sides. This will supposedly give the wheels I can order a "deep dish" look. Is this a common mod? What size of 17" wheel and backspace would work in there and what size tire would fit? Does this really give it a much deeper look?

[Z06vet]

This should allow you to order wheels with less backspacing, giving you more lip on the front side. I don't know much about the specs on the GTO, but one of the wheel sponsors on this site can help you out with the numbers.
Scott

[wmhjr]

If you don't modify the wheel houses themselves, you're going to have a very tough time fitting even a 275 tire back there. Look inside your wheel well and you'll see that even if you roll and trim the lip, the walls go up, then have another contour or large lip that protrudes further toward the wheel. I did a good bit of trimming and modification back there, removing as much as possible. It allows me to run 275s pretty safely, however I have just about zero extra space. Mine is a '66 which is effectively identical to a '67. If you notch the frame and move the inside of the wheel well toward the center of the car you can make more room, but other than that, the frame itself is the limiting factor.

If you do order the rear end a bit narrower, I'd suspect you will be able to use less backspacing, giving more of that "dish" look you're looking for. You just need to be careful to insure that you don't move it too far. I'm running 6.125" BS on a "standard" width Moser rear end, 10" rims, 275 tires. Even with that, my tires can slightly rub the frame. You won't be able to do the same most likely.

[JayR]

If you plan to narrow the rearend, you should always order the wheels first. Far easier to mock them up and measure between to determine rearend width than it is to measure for the wheels. Your car will hold 10s in any diameter you want with whatever amount of dish looks good to you, then put them in the wheelwells with tires on them and determine your rearend width. Cheap insurance by switching steps.

[DriverzInc]

I'm with JayR on this one. Its much better to order your wheels with the backspace/frontspace you want first, then narrow your rear end to fit, but of course, within reason. On a 10" wide wheel, and assuming a 275 wide tire, I would recommend building your wheel with a 5" backspace, and then mock that up in your wheel well and narrow your rear end from there. On a 10" wheel (which measures 11" overall) you will be left with 6" frontspace, and about .75" more wheel lip then you would normally have with a stock length rear end.

[wmhjr]

Just to be clear, I realize that you wheel vendors have more experience. However, the '66 and '67 rear wheel houses are identical on GTOs. I cut both the lip and trimmed the moldings on the lips of mine, and I removed those "ledges" from inside. I seriously considered running a little larger than 275s after that but am very glad I did not. I have essentially no clearance whatsoever on the frame side (the frame to tire clearance) and not a lot on the outside. Jon, as you know I'm running your 18x10 6.125" bs splitters mounted with 275 nt05s. Just wanted to provide a little caution. I also have to say I'm running 3" exhaust and there is also no clearance there either, but that's another story.

[Nicks67GTO]

Thanks for the replies gentlemen.

Cutting and notching the frame and wheel wells isn't really an option for me. Part of the deal with the car is that I want to make mods to it but be able to go back to stock should I have to sell her some day. Its a numbers matching 67' California H.O. GTO and I don't want to start cutting on that. I know its not the pinnacle of automotive value but they don't give them away.

WHMJR, I appreciate the GTO input. I currently have Weld Pro Stars on the car. I believe they are 15x8's with a 275/60/15 tire and I never had rubbing issues and if memory serves me correctly, I believe I have at least an inch and a half, possibly more on the frame side of the wheel. Would my 275's be a lot more narrow than your 275's because of wheel width??

[ProdigyCustoms]

Below is a 67 GTO we did that got a narrowed rear, 265 tires on 9" rims. Has a nice real deep lip.

I do not have all the measurements tonight, but have them at the office, but this is close to 3/4" per side narrow.

We just delivered a narrowed Moser last week to a customer in Cali for a 67 GTO. Identical set up

Your welcome to call tomorrow and I will share the measurments

https://static1.pt-content.com/images/noimg.gif

[PTS]

Hello,

Do you have a straight edge and a tape measure handy? PM me your phone number and I will call you and explain how to get 2 measurements and I can tell you how much negative backspace you can get. Very easy...

Regards,

Perry
PTS

[PTS]

Ordering wheels with a estimate of backspace for a car with stock suspension, stock outer fender lips, stock inner fenders is a big risk. Too negative and you rub the outer fender lip, too much positive and you rub the inner fender well, exhaust, etc... Lets measure your number matching ride.

Thanks,

Perry
PTS

[wmhjr]

WHMJR, I appreciate the GTO input. I currently have Weld Pro Stars on the car. I believe they are 15x8's with a 275/60/15 tire and I never had rubbing issues and if memory serves me correctly, I believe I have at least an inch and a half, possibly more on the frame side of the wheel. Would my 275's be a lot more narrow than your 275's because of wheel width??

Can't say. I just know what kind of clearance I have and what I had to do. Changes in the specific tire mounted on the specific wheel will certainly happen I realize. But I have probably 1/4" clearance, maybe 3/8" at the most. As you might expect one side is slightly different than the other. But both are pretty darned close. And like I said, that's after cutting. If you take your rear wheel off and look straight up in the wheel well, you'll see how the area has another bit protrusion inside the fender lip. Depending on how the car sits, if the tires are at all tucked up, it creates an issue. If your car is not lowered and you don't have much backspace with a relatively short tire, I can understand that clearance may not now be an issue.

[RF GTO]

I recently measured and ordered wheels for a 67 Lemans, and like WMHJR has pointed out wheel fitment on the 66-67 GTOs is tough. A lot depends on the width of your rear end. There are 2 widths available on the A-bodies (The new style is generally referred to for 68-72 A-Bodies and is 1/2" wider per side...However, Pontiacs started using the wider rearend in late 66 for the GTO/Lemans). You definitely need to get back there and measure.

My car has its original wide style rear end and I had 7.25" from the face of the rear disc brake rotor to the inner wall (toward the inside of the car) and 4.25" from the face to the outer (outside of the car). I ended up going with an 18x9.5 (effectively 10.5 total width) with 6.5" of backspacing and a 275 width tire. Needless to say, things are REAL tight back there and I may have to get creative with some slight modifications.

WMHJR - which rear end did you have in your car - the wide style or the narrow style?

Tyler

[wmhjr]

Tyler,

Actually, I originally had the narrower 8.2 BOP, however that was immediately discarded. I built the car with a Moser crate rear end built to the standard "narrow" spec. I think the key point is that the type/width of rear end will dictate your backspace requirement, but the wheel houses and inner fender/frame itself will limit the total width available. I know Jon said - and has done - 295s back there but that is also I believe with modified sheet metal inside, and it's really tight. I elected 275s and am glad I did because it's still close close even though I did the mods.

[egill3388]

Sorry to get off topic, but ProdigyCustoms what rims are those and do they come in black?

[ProdigyCustoms]

Those are Boze Tach wheels we custom painted silver, but we can have them done in powder coat black either gloss or satin