overall tire diameter for a 69 chevelle

[69496]

looking for a little input. I am getting some 18" wheels for my 69 chevelle. I am not sure if I should go with 35 series or 40 series tires. My choices are 305/40 (27.6") or 305/35 (26.7") for the rear
and 275/40 (26.4") or 275/35 (25.6") for the front. I am leaning towards the taller tire as chevelles are pretty big but I am worried I might be going too tall. If you are running something similar please chime in and let me know if you are happy with the size you ran or wish you would of gone taller/shorter?

[shep]

I think the 275/40 will be just a little too tall on the front, it will rub if you keep the inner fenders. the 305/40 should be fine on the rear as long as it doesn't rub the side on the quarter lip.

[Roadbuster]

looking for a little input. I am getting some 18" wheels for my 69 chevelle. I am not sure if I should go with 35 series or 40 series tires. My choices are 305/40 (27.6") or 305/35 (26.7") for the rear
and 275/40 (26.4") or 275/35 (25.6") for the front. I am leaning towards the taller tire as chevelles are pretty big but I am worried I might be going too tall. If you are running something similar please chime in and let me know if you are happy with the size you ran or wish you would of gone taller/shorter?

I have 255/35R18 up front and 305/35R18 in the rear. I am very happy with the rears, they fill out the wheel wells nicely. I had to go with a smaller front than you are looking at to clear the back of the Pontiac fender.

https://static1.pt-content.com/images/pt/2009/03/08153NK30626-1.jpg

Jon

[69496]

Jon,

Great looking pontiac. Wheels and tires look great. I am running the same suspension setup as yours. How do you like the size of your front tires. Does it work well in the turns or if you could would you of gone bigger in the front.

Mike

[Roadbuster]

Jon,

Great looking pontiac. Wheels and tires look great. I am running the same suspension setup as yours. How do you like the size of your front tires. Does it work well in the turns or if you could would you of gone bigger in the front.

Mike
Thanks for the compliments :)
I like the size of the fronts for response. They are nice and crisp. The tires are even with the rim. The largest I can run with my set up would be a 265 and still have clearance at the back of the front fender. With a Chevelle you can run a larger front tire due to fender design. Just run a larger rim to match.

When I was doing my research here (and some personal experience) I found the trick to response is to match the tire to the rim. With lots of bulge the response is dampened. With the tire stretched on the rim, the response is crisper. I don't like the skateboard look with the tires stretched so I go with a square sidewall or a slight bulge.

When I ordered my wheels and tires from Frank, he confirmed how the tires would fit on the rims.

Jon

[tom_a]

I have 305/35/18 rear and 275/40/18 fronts. From an angle and rear views it looks OK but from the side I think a taller rear tire may look better as in 305/40/18 IMO. I am going to try a few types of tires once I get up an running.
https://static1.pt-content.com/images/pt/2009/03/IMG00018200902281318-1.jpg
https://static1.pt-content.com/images/pt/2009/04/wheels005-1.jpg
https://static1.pt-content.com/images/pt/2009/04/IMG00013200902281308-1.jpg

[69496]

Thanks for your input Tom. I think I will go with 40 series tires. The way I am going to drive it they won't last long anyways if I don't like them. Now I need to get Nitto to make the NT05 tire in 305/40. All I have found in that size is their drag radial but that will do just fine for now.

[USAZR1]

I ran 275/40/17 Kumhos on the front of my 69 El Camino and they fit fine. My front wheels were pindrive/knockoff 17x9 PS Engineering Kidney Beans w/5.25" backspace.
With an 18" wheel,I would suggest a 275/35/18 front tire.

[andrewb70]

Taller is better. I am running 295/40-18s in the rear and 255/40-18s in the front. They are about 27" and 26" respectively.

https://www.pro-touring.com/%7Eandrewb/gtov2/photo129.jpg

Personally I would not go shorter. 305/40-18s and 275/40-18s would look killer.

Tom,
The new wheels look amazing! What size and offset are the fronts?

Andrew

[tom_a]

Hi Andrew,

Thanks. The fronts are 18 x 9.5" with 5.75" BS. My only concern so far is the sway bar, but I will have to wait till I get it on. Worst case I can change the back space. Hope grad school is going well.

[gmorris]

275/35/18 and 315/30/18 on mine


https://static1.pt-content.com/images/pt/2009/03/3377217221_deafcfecf3_o-1.jpg

[COPO-RAT]

Hi Andrew,

Thanks. The fronts are 18 x 9.5" with 5.75" BS. My only concern so far is the sway bar, but I will have to wait till I get it on. Worst case I can change the back space. Hope grad school is going well.


What width rear wheel are you running with the 305/35/18 tires?

[tom_a]

What width rear wheel are you running with the 305/35/18 tires?

18 x 11" with 6" BS

[69496]

tom a,

Obviously you are not driving your car yet. But do you see any possible rubbing issues running the 275/40/18 in the front? About how much lower from stock will you be in the front. And are you happy with the size of your front tires, do they look too tall at all or just right?

[tom_a]

tom a,

Obviously you are not driving your car yet. But do you see any possible rubbing issues running the 275/40/18 in the front? About how much lower from stock will you be in the front. And are you happy with the size of your front tires, do they look too tall at all or just right?

I really can't say for sure if I will have any problems so the jury is still out. "gmorris" car is one of the few finsihed 69's I have seen with 275's and his looks good with the 275/35/18. I guess if I keep the rear tires I may change the front but I don't care for my short sidewall on the 305 in the series 35. Nitto makes a DR in a 305/40 which may be better at filling the rear. My long term plan includes having two sets of wheels and tires.

[69496]

Toma,

I feel the same way about the short sidewall on A-bodies. The 35 series just looks a little too short in the rear. Unfortunately, especially for autocross tires not too much in 40 series. I want to try the NT05 from Nitto but the best they have is a 295/35 or a 295/45. I emailed them already about making something in between, preferably 305/40/18. All they said is that they are considering more sizes but didn't specify what size. If I could afford 18x11 wheels a good compromise might of been 315/35.

[gmorris]

The only issue I have with the shorter sidewalls (personal taste aside) is that it really holds you to a narrow range of ride height. I'm in the process of making some major suspension changes and the toughest part has been getting the height right again so I don't end up with a big gap between tire and fender. If the height is right the short sidewall looks good but if you're even a half inch to high they look bad real fast.

[69496]

Again I agree about short sidewalls and ride height. Your chevelle looks great with the 35 series because it is tucked up nice. Others I have seen that sit up even a little bit just don't look right with a gap between the fender and tire. How low did you have to go in the back from stock to get them to tuck like that? Are you running springs or coil overs?

[gmorris]

I actually have no idea how much it's lowered from stock because I have never had this car together stock. I'm running a 5.5X11 single pigtail rear spring at 200lbs/in right now. I'm actually waiting for my new SPC springs, swaybars and varishocks to show up right now and I'll have to try and get the height the same again. My stock bilsteins are not working with teh 850/200 springs I'm running now. I'm going to try moving to lighter springs with better damping and proper sway bars and see how it works.

Just for the record my rears are actually 315/30's, not 35's.

[DriverzInc]

Remember ride height is going to play a huge part. If you plan on lowering your car significantly, Then I'd run the 275/35 and 305/35 all the way around. If the car is only going to be dropped say 2", then you can get away with the 305/40 on the rear. I'd still run the 275/35 up front though. You don't want too much sidewall up front. Again, it all depends on stance.

[DriverzInc]

18 x 11" with 6" BS

Not to hijack this post, but Tom, are those the Nittos I mounted? Looking good. I like those wheels, one of my favorites from Fikse. Did you see we are a dealer now? ;)

[69496]

I actually have no idea how much it's lowered from stock because I have never had this car together stock. I'm running a 5.5X11 single pigtail rear spring at 200lbs/in right now. I'm actually waiting for my new SPC springs, swaybars and varishocks to show up right now and I'll have to try and get the height the same again. My stock bilsteins are not working with teh 850/200 springs I'm running now. I'm going to try moving to lighter springs with better damping and proper sway bars and see how it works.

Just for the record my rears are actually 315/30's, not 35's.

Sorry I mis quoted the tire size, You got some pretty stiff springs there. I will eventually get coilovers but I will probably do a 175lb rear spring 5.5 x 11 for now. How much lighter are you planning to go with the springs? And whatever your ride height is it looks great. Probably the best 69 I have ever seen. Hopefully I will get to see it in person.

[gmorris]

The SPC springs are 535/135 I believe. They may end up being too light but Mark at SC&C figures they will be a good startign point with eth varishocks. I'm also installing the new spohn adjustable PT rear bar. I may end up goign to a 150-175 11" rear spring again if need be. The main issue is teh front springs. I currently have 5X9.5" springs with a hidden adjuster. I personally hate the adjuster as it's a pain to adust, makes horrible noises every time you jack the car up and it's difficult to position perfectly so it won't rub the shock bodies. It's tight with the small bilsteins and they's no way I would try it with the varishocks. That means I'm stuck with a stock style lowering spring and shims. Not a big deal except you are limited to about 680lbs/inch max.

It will be an interesting experiment to see the change from what it is now. With the seriously uderdamped shocks and heavy springs it's great in a sustained corner but it sucks over rough pavement or rapid transitions. The ride is okay but it's really floaty and skitterish due to the shocks.

[69496]

Gmorris,
Are you running the SC&C upper and lower control arms and ATS spindles?

[gmorris]

I'm running SPC uppers and lowers with stock spindles and tall balljoints. I already had the Kore3 al hubs and C5 brackets so I stayed with them rather than switching over to AFX spindles.

[tom_a]

Not to hijack this post, but Tom, are those the Nittos I mounted? Looking good. I like those wheels, one of my favorites from Fikse. Did you see we are a dealer now? ;)

Thanks Jon,

Sorry for the delay as I did not see your post, but yes they are the Nitto's that I got from you and thanks again for the quick service. I may see you again soon as I kinda think you were right about the 275/35/18 in place of the 275/40/18. I really need to see where it sits once it has all the weight on it.

[andrewb70]

275/35/18 and 315/30/18 on mine



Gary,

What size wheel and backspacing?

Andrew

[gmorris]

18X9.5 front, 18X11 rear. Can't remember excat BS off the top of my head since I ordered them over a year ago. I believe the fronts are 5.5 or 5.75 and the rears are 6.25 or 6.5...I bounced back and forth a lot when I ordered them dealing with pad thickness and hub dust cap clearance issues. I missed a bit on the rears as I still have just over 1/2" to the frame rail and a lot less to the fender lip. Tire hasn't touched the fender yet but I'm going to roll the pinch weld lip a bit this weekend just to be sure I don't cut the sidewall when I get it on the road course next month.

[andrewb70]

18X9.5 front, 18X11 rear. Can't remember excat BS off the top of my head since I ordered them over a year ago. I believe the fronts are 5.5 or 5.75 and the rears are 6.25 or 6.5...I bounced back and forth a lot when I ordered them dealing with pad thickness and hub dust cap clearance issues. I missed a bit on the rears as I still have just over 1/2" to the frame rail and a lot less to the fender lip. Tire hasn't touched the fender yet but I'm going to roll the pinch weld lip a bit this weekend just to be sure I don't cut the sidewall when I get it on the road course next month.

Thanks! I am kicking myself in the ass for not getting wider front wheels.

Andrew

[13OZKAR]

i have 305/35/18 rear and 275/40/18 fronts. From an angle and rear views it looks ok but from the side i think a taller rear tire may look better as in 305/40/18 imo. I am going to try a few types of tires once i get up an running.
https://static1.pt-content.com/images/noimg.gif
https://static1.pt-content.com/images/pt/2009/04/wheels005-1.jpg
https://static1.pt-content.com/images/noimg.gifnice!

[13OZKAR]

275/35/18 and 315/30/18 on mine


https://static1.pt-content.com/images/pt/2009/03/3377217221_deafcfecf3_o-1.jpgvery nice!

[13OZKAR]

i have 255/35r18 up front and 305/35r18 in the rear. I am very happy with the rears, they fill out the wheel wells nicely. I had to go with a smaller front than you are looking at to clear the back of the pontiac fender.

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

jonnice!