Hey guys,
I have the old 15 inch Weld ProStars on the car now with skinnys in the front and huge MT in the rear
When I first built this car 20 years ago, I wanted that look
Now, I am upgrading the suspension , brakes and I want to put some 18 inch wheels that work great

I need to know the correct Backspacking - I think 4.5 inch correct ?
Also What size RIM can I go in the front 9 inch ?
and the Rear ? 10 Inch ?

Any Hot Rods with an 18 inch wheel set up , I would love to see it

Love the help

 

Real Hot Rods don't run 18! Ughh! You got a damn good looking car there. Don't fall for BS trends. Keep what you got or put some classic cragers SS's on that rod! My 69 Olds is in my profile picture. I even have Bias ply Tires. Nothing looks better on a classic car . Nothing!

 

I'm afraid you need to understand the difference between backspacing and offset. Offset is the distance from the wheel mounting surface to the centerline of the rim. For these cars, offset needs to be close to zero. Backspacing is the measurement from the inboard lip of the rim to the wheel mounting surface, and is dependent on wheel width. For zero offset, backspacing is slightly over half the wheel width (plus the thichness of the lip on the wheel). A 7" wheel with zero offset would have about 3.75" backspacing. An 8" wheel with zero offset would have about 4.25" backspacing. You can't specify backspacing needed for a car without knowing the wheel width also.

As for the rim size, fitment depends on the TIRE size you plan to run. Without knowing that, it isn't possible to provide a meaningful answer.

 

Search a post by Mr Nick, he's running 18's. I'm going with 17's on my 71. 17x9.5 with 5" BS in the back and 17x8 with 4.5" BS in the front.

 

I love the class 14" - 15" rims that originally came on these cars. However, I also think a good set 17" (maybe 18") can give these cars a nice, modern, aggressive look. Obviously, its personally preference. Post pictures of the before and after when you get the new "shoes"

 

BS trend of improving the performance of his car? Wasn't putting Cragars on everything a trend that just never went away?

Anyway, as mentioned I have 18's on my car, partly because they were required to fit over the larger brakes.



https://classicoldsmobile.com/forums...18-wheels.html

Feel free to ask any questions you may have.

 

Those look great on your car. Nice pic

 

I don't have my car back together yet, but I'm running these on my '72 442 convertible. I bought them from Summit Racing for the free shipping. I'm planning to fit the original SSI center caps but need to design some kind of retainer as the stock retainer will not fit inside the hub.
Rear - 285/40 on 18x9
Front - 245/45 on 18x8

 

Car can look nice, modern and aggressive without big rims.
It's an old picture, rear has been lowered another 1" since.

 

cdrod - Those look great! Excellent choice on the tires, both sizing and the Conti's themselves. You will be happy!

 

70Cutty-the wheel/tire presentation, combined with the stance, pretty much nails it for me.
NICE JOB.

 

MikeyBee455 - I totally understand where you are coming from. I have always liked the so called drag race look, you know what I mean. The classic "Big n' Little" style with a slight rake. However, I went to a couple of Goodguys events and watched the guys with tricked out GM "A" bodies flying around those courses they set up for them and those cars look sweet. They're all running 18" wheels with wide tires all the way around.

My 65 442 currently has 15 x 7 and 15 x 8 SSI's, and I will always like that wheel on an early Cutlass, so I plan on keeping them. I also have a new set of 18 x 8 and 18 x 9.5 Ridler 645 wheels I plan on using this summer. That's my point about wheels being like shoes. I have more than one pair of shoes, and I wear different styles. I think the same way about my car, if I get tired of one look, I will bolt the other ones on for a while.

Of course, my disc brakes will fit with both the 15 and 18 inch wheels. If you decide to go with some of the "Big Brake" kits your old 15 wheels might not fit anymore. I didn't want to limit my choices, so I picked what would work for me.

 

Yeah I have a question. what and where did that Chrome strip running down the side of your car come from?!

 

One the 1/4 panel? The car originally had a vinyl top, previous owner had it repainted but for whatever reason never had the vinyl top re-installed or forgot to tell the body shop to fill the holes for the trim.

If you mean the stripe on the belt-line, it's just a pinstripe added by the previous owner as well.

Was given some old Polaroids by the selling when I bought the car:

 

Okay cool, thanks for posting the Pics.

 

Nick:
Thanks for the affirmation on my wheel and tire choice. I agonized over these decisions and did hours of research on Tirerack.com and other sites to select a tire with the best wet & dry traction, corning and mileage performance.
Rodney