18" Tire Recommendations -- Need some big help

[Cars4Kids]

Hey guys.....we are rebuilding a 69 Nova and will be installing the following wheels:

Front: 18x8 4.75 backspace
Rear: 18x9 5.75 backspace

I am hoping one, or more, of you might have some recommendations of "safe" tires for this build....ones that will fit the wheels and the wheel wells

Any help will be appreciated since the other site the kids frequent has NO responses and we can't just buy a few and try one at a time

thanks
cars4kids

[MarkM66]

I'd do 245/40 front, 275/40 rear.

That's close to what I ran on my '70, and they worked fine. I only had a 7" wide wheel in the front, so I went with a 235.

[johnny68]

talk to Jon at driverzInc 951-609-3483 he and his crew are the greatest and also Mark is right on with his sizes (find Marks old car and check it out its inspiring)
i will have a 245/40/18 on the front our nova with a stock clip but lowered the back ive tubbed with a 315
John

[Cars4Kids]

Thanks.....any others who can chime in it will be great. Last evening through some research on this site I was able to get these same results and you just help in the reassurance.

I got them with the best backspacing available since I can move them OUT with spacers but can't do diddly about moving them inward due to too little backspacing.

Thanks again.

PS.....I can do just about anything but what I don't understand is how the 35 or 40 on the rear will affect the "balanced" look with the fronts at a 40. Educate me.

[Norwood]

I'm using 8 F 5" BS and 9.5 R 5.5" BS with 245/40 275/40 on Vintage V-40's with nitto NT-05's.
https://static1.pt-content.com/images/pt/2011/08/1231831690_oEtxKL-1.jpg

[muthstryker]

PS.....I can do just about anything but what I don't understand is how the 35 or 40 on the rear will affect the "balanced" look with the fronts at a 40. Educate me.

Wider tires are always taller.

Example

Nitto INVO tires

Rear Tire 275/40/18 = 26.65" Tall

Front Tire 245/40/18 = 25.75" Tall
Front Tire 245/45/18 = 26.69" Tall

[wmhjr]

Wider tires are always taller.

Example

Nitto INVO tires

Rear Tire 275/40/18 = 26.65" Tall

Front Tire 245/40/18 = 25.75" Tall
Front Tire 245/45/18 = 26.69" Tall

OK, to add on...... The ASPECT ratio is different between the two 245s you show. The width is the same. The amount of sidewall is different. Specifically, while both of those tires have the exact same identical width, the 45 aspect ratio has a taller sidewall and it makes the tire taller. Look on the Nitto site for specs on the 275 NT05. Both the 275/35-18 and 275/40-18 have the exact same width of 10.79". However, the 40 has a taller sidewall, resulting in a taller height.

Now when you compare the 245 to the 275 and keep the aspect ratio the same, the sidewall will increase slightly as well making the tire slightly taller. That being said, IMHO you get more of a "balanced" perspective by concentrating on the sidewall height than the overall tire height. Don't know if that makes sense.

[muthstryker]

Thats what I was trying to show, you just made it a whole lot clearer then I could.

[Cars4Kids]

WMHJR.....

two things.....

- Your suggested tire sizes would be?
- Where in Pgh are you from? Me...North Hills

[JustinB]

Cars4Kids, PM sent your way.