[DKS]

My 1970 GTO came with 14 inch rally two wheels and has 225/70–14 tires. The previous owner did some suspension work and replaced the front springs 1 inch lower and the rear springs 1/2 inch lower. This makes the car sit very nice, but I’ve always had vibration problems and I am narrowing it down to bad wheels and or tires. Cooper cobra radials. I’m considering replacing the rally two wheels with reproduction 15 inch, either seven or 8 inch wide I guess?? And maybe 60 series tires??But I am worried something might rub because of the slightly lowered springs. Anyone have any experience with this? And has anyone had good luck with reproduction rally two wheels? I would hate to replace everything And find out the new wheels are as crooked as my original ones. Thanks.

[indymanjoe]

I wonder if lowering it may have changed your pinion angle? may want to check that. rally 2's in 15" in my opinion really fill the wheel openings nicely.

[DKS]

I think I’m ok on the pinion angle. I spent all day today swapping my spare tire with each corner one by one and making a freeway run. 4 runs and $50 in gas later I found I have two bad wheels and/or tires causing the vibration, even though I’ve had them balanced twice.

I always liked the fit if the 15” wheels better and thought this might be the time to swap them all out. I’m just worried about rubbing since the car is 1” lower, especially if I go to 60 series tires.

[JLMounce]

With a 15" wheel, lowering the car doesn't generally introduce any new obstacles to added wheel width. Those obstacles are typically the lower shock mount in the rear and the outer tie rod in the front. These are positioned in a manner that as you go wider, or inset a wheel more, you start to contact these parts.

Once you get into 17" wheels and larger, these pieces start to slip inside the wheel hoop.

I have not played around with an A body and small diameter wheels, so I can't even hazard a guess on how wide you can go and at what offset. Your best bet is to get your straight edges out and start measuring what is possible with you car.

On your pinion angle, if you have the factory control arms in the rear, I wouldn't be too quick to discard that possibility. The factor non-adjustable upper and lower control arms will be out of pinion spec even with minimal lowering. They typically either need cut and rewelded to proper spec, or a set of adjustable arms are needed.

[Shiny]

Just a thought...

Recent Thread About Lug Centric Balancing

[DKS]

Good advice everyone, thanks, more things for me to check out.
Shiney, funny you would mention that thread. I did see it and learned how difficult it can be to find someone to spin balance the rally 2 wheels the correct lug centric way. I actually found a guy who had a lug mount setup for his tire shaving and balancing machine. He trued up the tires and balanced them, but advised me that a couple of the wheels were not very straight. Apparently enough to still cause vibration over about 65mph.
I think I’ll just look for a couple replacement 14” stock wheels. Of course then I’ll have to have those two tires shaved again since they were ground to fit the wonky wheels…

[mrennie]

I balanced 4 stock 15" Rally 2s and 2 Wheel Vintiques 15" Rally 2s.

The stock wheels are certainly not well made. Noticeable wobble even when balanced with lugcentric adapter. The WV were straight as an arrow.

I used Cooper Cobras on the stock wheels and Nitto drag radials on the WV wheels. The Cobras are also not well balanced compared to the Nittos.

Required A LOT of weights to balance the stock wheel/Cooper combo, and very little weight for the Nitto/WV combo.

I have a vibration that starts over 65. Not pleased about it but short of searching for better wheels and the extreme hassle of painting them, I'll live with this for now.

[scott70]

Also when you look for used 14’s you have to look at where the lugnut sits in the taper. Most rims have been put on and off cars many times and the taper hole gets wallowed out. They make special washers to use with worn seats but obviously not ideal.
As far as rubbing if the tire height and width is the same as now it really doesn’t matter if it’s 14,15,17 inch as long as offset and rim width is the same.

[android 211]

Pontiac hasn't made Rallye II 15" since the eighties and your wheels could be 40 years old; countless potholes, curbs etc. Before you go to the trouble of painting a set of wheels you have to spin them and look for runout without a tire. . I made the mistake of sandblasting and painting a set of wheels and found out one had a visible wobble when mounted. It did balance and there was no shimmy in the steering wheel but my wife told me about it so we switched cars so I could see and it was pretty severe. Its spare until I do another set of wheels. Use a piece of coat hanger as a pointer and spin the bare wheel and look. Used wheels are still pretty easy to find on Craigslist locally where I live. There are 6" 14s and 7" 14s. 7" looks better. I think 6" is correct for '70. There was a 15" wheel option in 71 and 72 but I'm not sure about '70. '70 Trans Ams had 15" wheels but there were unique, they had 14" center hubs and a rim bent to match. They used F60s (235/60-15) while the GTO had a G60, 245/60-15.

[Red Box Rebel]

My '68 GTO ran 14"x6" Rally IIs for many years. I just recently switched to 15"x7" Rally IIs with 215/70R15 Tiger Paws from Uniroyal. I am 1" lowered and have no clearance or turning problems with this setup.
I would not go with the 225/R7015s or 60 series without doing a test fit. Any tire bigger than 215/70R15s may have clearance problems.
I bought a new set of 15"x 7" Rally IIs from AMES. Good quality, but I decided to repaint to match the color coding of the body color of the car.
Grey for the back side, Silver for the spokes and Meridian Turquoise for the non-spoke ares. They look fantastic!