[chiphead]

That's close to what I'm looking for. I'm just wanting enough sidewall so it looks right and the ride isn't too stiff.

What wheels are those?

[69gtocv]

I know you're dealing with a 67, but here is my 72 for reference. I went with 18x9.5 in the back with 5.25" backspacing on a 275/40/18. These are Ridler 650's. Fronts are 18x8 with 4.5" backspacing, running 245/45/18

[JLMounce]

Originally Posted by chiphead

That's close to what I'm looking for. I'm just wanting enough sidewall so it looks right and the ride isn't too stiff.

What wheels are those?

The wheels are American Racing Rodder's. 18x8 front and 18x9.5 rear. These wheels only come in 0 offset though. They were fine on the back, but desperately needed between 8-10mm of positive offset on the front. They rubbed pretty bad on a lowered car. They would be fine on a car that is not lowered.

Tire type and construction really matters here. As an example, my 69 bird rides nicer with it's current tires on my 18" wheels than it did with the previous tires on 17" wheels. It's all in the construction and purpose of the tires.

Previous tires were Falken Azenis 615K+ in 245/45/17 and 275/40/17. About 4.5" sidewall

Current tires are Nitto NT555 G2 in 245/40/18 and 275/35/18. About 4" sidewall. The nittos ride much nicer because they are not a competition tire. They naturally have more give in the sidewall. They also don't have the grip those Falken's had...compromises.

In fact, I'd really recommend the Nitto Invo's if you are concerned with ride quality. These are designed as a luxury performance tire. So they have decent grip, but the sidewall is soft comparatively to provide a nice ride with quiet road manners.

[67Lemons]

Can you go with 17” wheels & fit those brakes? My ‘67 is running 17x8” in the front & 17x9” in the rears with no rubbing using the Year One Rally 2’s.

[vertigto]

My 18s for reference...

[b-man]

18x8” all around on 235/40-18 tires.

Crazy that a 2023 Civic Sport comes equipped that way now as standard, and it’s their lowest priced Civic.

It’s kinda like a Pontiac……you know 4 wheels and all that.

[69gtocv]

Originally Posted by b-man

18x8” all around on 235/40-18 tires.

Crazy that a 2023 Civic Sport comes equipped that way now as standard, and it’s their lowest priced Civic.

It’s kinda like a Pontiac……you know 4 wheels and all that.

Just an fyi for the OP, a 235/40/18 is pretty short at 25.6", not sure that's what you're after, definitely not 29" though either.

[chiphead]

So I call a local tire shop and ask for a quote on some 215/45/ZR18 DWS06 tires for the front. The guy tells me the '67 GTO exceeds the load index of those tires, and the smallest front tire he recommends is a 235/45 R18 for the front.

I know a 215's 8.4" section width will fit, no idea about a 235's 9.3" section width on a 8" wheel with 4.5 backspace??

What gives, and will a 9" tire even fit the front of a '67 GTO?

[JLMounce]

235's on an 8" wheel are fine. You'll get a little bit more sidewall out of it as well.

[Joe-Touring]

Originally Posted by 67Lemons

Can you go with 17” wheels & fit those brakes? My ‘67 is running 17x8” in the front & 17x9” in the rears with no rubbing using the Year One Rally 2’s.

17s CAN fit, but not guaranteed. 18s are said to be an easy fit.

I currently have a Kore3 C5 setup on my 67 LeMans, running Trans Am Race Engineering Superlite wheels, 17x8 4.5” backspace/0 offset. No fitment issues.

Previously I had Cragar Soft 8s with the same specs as the above, but the fronts needed a small spacer(~10mm I believe) to clear the front caliper brackets.

So it is possible. Kore3 has templates you can print out to either send to the wheel manufacturer or measure yourself.

[Joe-Touring]

Originally Posted by chiphead

know a 215's 8.4" section width will fit, no idea about a 235's 9.3" section width on a 8" wheel with 4.5 backspace??

What gives, and will a 9" tire even fit the front of a '67 GTO?

I run 245/45/r17s all the way around on my 67 LeMans. I have a slight rub on the front going over large uneven bumps. I do have a bit of rub in the rear because I have a wider 69 Chevelle 12 bolt.

[vertigto]

FWIW...I'm running NITTO NT555 G2 (245/45R18) up front on US Mags Rambler 8" wheels with 4.5" backspace/1mm offset & 275/40ZR18 on 9.5" wheels with 5.25" backspace/1mm offset...no rubbing issues.

[HWYSTR455]

So tread width and section width are 2 diff things, and you need to take both into account.

The tall the tire is, the wider the section width gets. The more narrow a wheel is, it can also make a tire wider. (in general)

You can look at specs of a tire and find diameter, sec & tread width, etc.

215s are way too small in tread width, that's like skinny/fat days, and not safe. 225s are too small but can work on some cars, lighter ones I would think. You can get away with a 235, but honestly, you really don't want to run anything less than a 245. 255 front/275 rear is the 'standard' performance setup.

A typical 245/45/17 tire has a tread width of 8.2", and a section width of 9.6" (dia @ 25.7"). If that fits for someone else, you basically can get a similar tire in an 18" with similar tread & section width.

Joe-Touring - What width wheel are you using, and what backspacing?

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[HWYSTR455]

Originally Posted by vertigto

FWIW...I'm running NITTO NT555 G2 (245/45R18) up front on US Mags Rambler 8" wheels with 4.5" backspace/1mm offset & 275/40ZR18 on 9.5" wheels with 5.25" backspace/1mm offset...no rubbing issues.

Unfortunately, a 70 is different than the 64-67s, and not a good example.

I run 275/40s all around on my 70, with 18x9.5 wheels, but have aftermarket upper control arms. Also not a good example.

.

[Joe-Touring]

Originally Posted by HWYSTR455

Joe-Touring - What width wheel are you using, and what backspacing?

8” wide TARE Superlites, 4.5” bs. Sorry, I posted all that in the previous reply, spose I shoulda put all the specs in both posts

[b-man]

Originally Posted by HWYSTR455

Unfortunately, a 70 is different than the 64-67s, and not a good example.

I run 275/40s all around on my 70, with 18x9.5 wheels, but have aftermarket upper control arms. Also not a good example.

.

Kinda why I posted a picture of my wife’s ‘23 Civic Sport Hatchback on 18x8s and 235/40s.

Not a good example……

Originally Posted by chiphead

So I call a local tire shop and ask for a quote on some 215/45/ZR18 DWS06 tires for the front. The guy tells me the '67 GTO exceeds the load index of those tires, and the smallest front tire he recommends is a 235/45 R18 for the front.

I know a 215's 8.4" section width will fit, no idea about a 235's 9.3" section width on a 8" wheel with 4.5 backspace??

What gives, and will a 9" tire even fit the front of a '67 GTO?

That guy at the tire store did you a favor, a 215 is a wimpy size and not even in the ballpark for a decent size tire.

Don’t be putting a little bitty front tire on it just to make sure there’s more than enough room, if you’re not running at least a 235 and better yet a 245 it’s not worth the trouble.

My suggestion would be to look at 4.75” to 5” or backspace on an 18x8” wheel, 4.5” isn’t enough. It’s understandable that guys running 17x8 or 18x8 wheels with 4.5” backspace are having rubbing issues even if just slightly, not enough backspace.

25 years ago in 1999 I had a set of 17x8” wheels custom built for my Tempest with 4.5” of backspace. That 4.5” backspace limited the front tire size to a 235/45-17, if I had another half inch of backspace I could have gone up to a 245/45 up front and in the rear a 245 or 255/45. So I’ve been there done that have the T-shirt.

Now sitting on 18x9” 5.5” backspace front and 6.57” rear backspace with 245/40s and 275/40s, will be changing to 245/45s in front to gain a little ground clearance and to match my 245/45 spare which also equals the height of my 275/40s. Having a spare that is a the same height as the rear tires and also fits in the front is important so you don’t burn up the clutches or otherwise overwork your posi unit, clutch type or not.

[chiphead]

Originally Posted by Joe-Touring

I run 245/45/r17s all the way around on my 67 LeMans. I have a slight rub on the front going over large uneven bumps. I do have a bit of rub in the rear because I have a wider 69 Chevelle 12 bolt.

Is your car lowered in the front? Mine is 1" drop.

[Joe-Touring]

Originally Posted by chiphead

Is your car lowered in the front? Mine is 1" drop.

Indeed it is, SPC springs, upper/lower control arms, and 0.5” taller lower ball joint. Hard to say exactly how much lower it is than stock, SPC sez 1.3” drop for the springs, and 0.5” for the ball joint. But I’m using their ride height adjustment kit, I think that adds back 0.5”. So let’s say 1.3” drop lol

Here’s some pics

[chiphead]

Wanted to close on this one. Thank you to all who provided very valuable advice. Here's the before and after. I went with the Bandit mags wheels.
18x8 4.5 BS front
18x9 5.3 BS rear
Front tires are 235/45-18, Rears are 255/45-18. Continental DWS06.

I removed the 1.5" spring spacers from the rear suspension, so the car sits level. Fitment is very good, front and rears seem to clear everything. With more rear backspace, a tire wider than 255 might fit. But I'm satisfied so far, the ride and handling is so much better. The late model wheels/tires really do make a big difference! The car feels more balanced, with more grip and confident feel in the front end. I'm excited to drive it more and see how it behaves.

Here's a before and after pic. Check out the size difference between the old skinny 205/75 front runners and the new 235/45 front tire.

[HWYSTR455]

That looks GREAT!

Now that you have those on, you can see if you can squeeze a 245 under the front. Does it appear if there's room? I know some are running them.

I had some DWSs before, but had issues keeping them balanced. Belt shift was a problem I had with the, so curious on how you make out.

They were great rain tires, that I do remember. Lately I've been running the General G-MAX AS-07s and am happy with those.

245/40s are the same diameter/height as the 235/45s, just to comment.


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