[Dayo5]

Total Newbie Question here...thanks for suffering.
I have a 1970 Pontiac GT37/GTO, it has the typical 5 bolt/nut pattern on the wheels---will all 5 bolt/nut pattern wheels fit my pattern? Or is it much more detailed than that? Thanks

[techinspector1]

Originally Posted by Dayo5

is it much more detailed than that? Thanks

In a word....yes.
Wheel sizing - Wikipedia, the free encyclopedia
Pay particular attention to "centerbore". Matching this will take the radial load off the studs/nuts.

[joe_padavano]

Originally Posted by techinspector1

In a word....yes.
Wheel sizing - Wikipedia, the free encyclopedia
Pay particular attention to "centerbore". Matching this will take the radial load off the studs/nuts.

That seems to be a euro-centric Wiki entry. Suffice to say that your Pontiac uses the 5 x 4.75" wheel bolt circle that's probably THE most common one for aftermarket wheels. I will guarantee, however, that if you DON'T verify the bolt pattern before buying wheels, you'll get the wrong one.

Also, your RWD car wants wheels with as close to zero offset as possible. That means you cannot use the FWD wheels that have a large positive offset. Offset is the measurement of how far the wheel mounting surface is "offset" from the centerline of the rim. Zero offset means that they are lined up. Positive offset means that the rim (and tire) centerline is further inboard than the wheel mounting surface, negative offset means that it is outboard. Unfortunately, most wheel vendors specify backspacing instead of offset, and that's not really useful without also knowing the wheel width and the additional flange thickness on the edges of the rim.

[cobalt327]

Originally Posted by Dayo5

Total Newbie Question here...thanks for suffering.
I have a 1970 Pontiac GT37/GTO, it has the typical 5 bolt/nut pattern on the wheels---will all 5 bolt/nut pattern wheels fit my pattern? Or is it much more detailed than that? Thanks

Here you go. You'll be looking for the 5 on 4-3/4" pattern wheels. There's more to it than just the wheel bolt pattern, things to look for are covered there.

Good luck.

[Dayo5]

This is great information-thanks so much!
Where did you look up my wheels being 5x4.75? I have been looking everywhere for that information and couldn't find it anywhere.

[496CHEVY3100]

Go to most tire stores pick up a progressive wheel handbook ,it will list bolt circle back spacing and center diameter for about all vehicles a big help , a T 37 Temrest a rare find your lucky, is it a t37 or gt 37

[joe_padavano]

Originally Posted by Dayo5

This is great information-thanks so much!
Where did you look up my wheels being 5x4.75? I have been looking everywhere for that information and couldn't find it anywhere.

Every GM RWD intermediate (Chevelle, LeMans, Cutlass, Skylark) built from 1964 to 1988 used the 5 x 4.75 pattern.

[timothale]

My son used a mustang steel spare wheel for his spare on a Lincoln Versailles 9 in rear. He went from N Calif bay area to LA, with the mustang wheel, He was " too busy" to get the correct aluminum wheel flat fixed. Some where in the middle of an LA freeway the wheel started to wobble. IT had several cracks. Lucky, the traffic jam had traffic only going 25 mph.

[496CHEVY3100]

Originally Posted by timothale

My son used a mustang steel spare wheel for his spare on a Lincoln Versailles 9 in rear. He went from N Calif bay area to LA, with the mustang wheel, He was " too busy" to get the correct aluminum wheel flat fixed. Some where in the middle of an LA freeway the wheel started to wobble. IT had several cracks. Lucky, the traffic jam had traffic only going 25 mph.

The mustang has a 4.5 x 5 bolt pattern the linclon 85 or newer have a 114 mm x 5 it will bolt on But will not stay tight when you start to drive.

[cobalt327]

Originally Posted by timothale

My son used a mustang steel spare wheel for his spare on a Lincoln Versailles 9 in rear. He went from N Calif bay area to LA, with the mustang wheel, He was " too busy" to get the correct aluminum wheel flat fixed. Some where in the middle of an LA freeway the wheel started to wobble. IT had several cracks. Lucky, the traffic jam had traffic only going 25 mph.

In theory if the centerbore is too large this can happen as well.

[Dayo5]

According to the VIN it is a GT-37

[cobalt327]

Originally Posted by Dayo5

According to the VIN it is a GT-37

Nice find. Not to disillusion you but it would prollably be more accurate to call your '70 a GT-37/Tempest. One main reason for its existence was to not be as "sporty" as the GTO (bench seats, stripped down) so it could be insured cheaper. That actually made it quicker than a lot of GTOs, though.

[Dayo5]

That's great! I would go a step further and call it a Frankenstein GTO/37...someone really hacked into it at some point wanting a GTO- they put on the GTO Hood, Endura front bumper, rear wing, and full GTO interior with buckets. I am still trying to figure out the engine, I am having a hard time finding the stamp on the block, I did find an "XS"...it has an edlebrock manifold into a rochester carb.

[cobalt327]

XS was used a lot. From a 301, 350, 389 and 400 in various years.

Links for ID'ing your engine can be seen at Pontiac engine info. You might also want to take a look at Pontiac info/sites.

[timothale]

the 9 in disc rear was out of a mid 70's. versailles. the mustamg center hole was a little bit smaller, but the bolt pattern was the same.the wheel lug area did not fit tight to the rotor.