20" and 22" wheels with tire sizes

[Slowguy]

I don't know why I am having such a difficult time getting any suppliers to respond. People simply just refuse to respond. They must be so busy they don't need the sales?? I just am trying to make sure before I order so I don't end up with something I can't use. Hopefully someone here has been in the same boat with a similar setup.

My plan is to use 20" up front, 9.5" wide.

The rear would be 22" by 11" wide.

I am leaning toward the us Mags U131 wheel in the 5x127 bolt pattern. I change the rear axles to yukon 5 bolt for this truck and the fronts to cpp 5 bolt disks.

I added 16" tubs in the rear but I have the stock 12 bolt axle with a trutrac rear end.

Questions here would be: what are your thoughts on the look of the 20" in front and 22" in rear. I've never staggered diameters like this but I've been told it's common in the muscle car/lowered truck arena. I have the rear frame c-notched and lower blocks on air, and the front has cups in the lower control arms. It can sit fairly low. fully aired out it tucks the wheels a few inches

what size tire would be best for the rear assuming i go with a 22"x11"? I assume I'd do something like 30 sidewall in the rear and maybe 35 or 40 in the front on the 20". Same question for the front.

At this point this is where I'm at:

Wheels: US MAG u131, bullet style. 5x127 bolt pattern. 22"x11" wide rear, 20"x9.5" front.

Tires: front: 265/35x20, rear 295/30x22

[lolife99]

Since you are on air ride those wide wheels need to be inside your fenders and bedsides.
I would be more worried about the correct wheel backspacing than I would tire size,… to begin with.
Most 8.5/10 wide combos work.
In my opinion you also don’t want the front tire sidewall taller than the rear tire sidewall.

[Slowguy]

Thanks for the response. Backspacing always confuses me. That's why I like to see or ask if someone has success with a similar setup. Much easier to let someone else do the testing first!

It says the BSM for the 20's is 5.29" and the 22's is 6.71"

[geezer#99]

I learned long ago to make my own measurements for wheel/tires.
Too much money involved to make mistakes.
Suppliers don’t respond because every tire/wheel figment is likely different even on similar trucks.
Found this years ago. Easy to figure out backspace, widths etc.
About 10bucks for parts to make measuring tools. There are better ones but can be 100 bucks. Best money you can spend. I’ll link it too.



https://www.motortrend.com/how-to/cc...heels-fitment/




https://www.motortrend.com/how-to/hp...nce-wheelrite/

[Slowguy]

wow! thank you for this.

[lolife99]

Just remember that those 9.5” front wheels actually measure 10.5” wide overall.
And those 11” rear wheels will actually measure 12” overall.
Advertised sizes are measured at the tires bead surface.

[Slowguy]

This is actually what I was after but the listing seller won't respond

https://www.ebay.com/itm/25510785963...rdt=true&rt=nc

[CC69Rat]

Lots of variables to contend with. Just to be sure I'd suggest measuring about 10 times at ride height. Just my initial thoughts:

Inner wheel houses in the front - are you using the stock ones or aftermarket?

Which CPP spindles do you have? The standard ones or modular?

Stock upper and lower control arms correct? Just cupped in the lower? Still the stock kmember?

Do you have the early or late rear end housing?

Wood floor bed or metal? Is the bed floor raised or no?

Discs on the rear or drums?

All trucks are different. I have learned the hard way man, build the truck how you want it then fit your wheels and tires to it, vs the inverse.

Ex 285/30r22 size tire.

Take the width (285) and divide it by 25.4. That will convert the metric size to inches. In this case = 11.22" wide.

The next number is the aspect ratio. So, in other words a percentage of the width as a decimal.

11.22 x .30. = the size of your sidewall. From the ground to the bottom edge of the wheel lip, and of course the top of the wheel to the top of the tire. = 3.36 in sidewall. X2 of course. One on top, one on bottom.

Then add your wheel diameter.

285÷25.4×.30x2+22 = 28.73" tall overall.

This may not be the size tire you're looking for, I just pulled some numbers out of the air to work with as an example. What I do is try to make the sidewall in the rear at least as big, if not a little bigger (taller) than the front. It's kinda hard to do to find the right combination when the wheels are staggered, but just mess around with it man. You'll figure out the right width and overall height (FIRST) then once you know the sizes you're wanting to go with, adjust the backspace to sit them in the wheel well where you want them to be. Keith touched on this a bit too, but it's really important for the overall look of the truck not to have the front sidewalls taller than the back ones. Just my opinion.

Hope this helps. I can help with backspacing too but I'll have a ton of questions.

[Slowguy]

Inner wheel houses in the front - are you using the stock ones or aftermarket? no wheel housings at the moment. I can deal with this later after all is complete

Which CPP spindles do you have? The standard ones or modular? drop spindles, otherwise standard disk conversion type?

Stock upper and lower control arms correct? Just cupped in the lower? Still the stock kmember? stock with cups lower and stock k member

Do you have the early or late rear end housing? original 67 so assuming early

Wood floor bed or metal? Is the bed floor raised or no? unfortunately didn't have the foresight to raise it and it's all complete so it's not. not wood, new metal floor

Discs on the rear or drums? drums for now, disc only in front

[Slowguy]

I watched a video here: https://us-mags.com/wheel-measure-guide-p-44.html
...and printed off the measurement form. I think I'll run down and measure it all up and just go with 20" all the way around. I'll make sure I don't cut anything close. I'll try and be conservative with widths just to play it safe but I know these wheels have been put on many of our trucks, I just can't get anyone to respond with specifics.

https://www.us-mags.com/bullet-u130-g-33347.htm
https://www.classiccarliquidators.co...-chevrolet-c10
and these are similar:
https://www.us-mags.com/c-ten-u129-g-30766.htm

[geezer#99]

Another measurement to watch for is tire sidewall to inner fender or frame. Anything it might rub on.
You need at least one inch clearance to be safe.
As an example if your tire is 12 inches wide then you’d want 14 inches of room to fit.

[CC69Rat]

As stated above, all trucks will be different. I'm in no way committing to these sizes but . If you order these, and they won't work for you man I cant be held responsible.

But - what I normally run on these trucks is a 20x8.5 and 20x10. On a truck as low as yours sounds, backspacing and wheel / tire to fender clearance will be an issue. I would highly suggest measuring and measuring again. But, here goes.

A 20x8.5 up front us about as big as I would go (personally) with stock control arms and a truck this low. You have to think about turning the wheels and stuff. Overall drivability
I'm not saying a 9.5 couldnt be done but.. just my opinion. I usually run 5.5 BS on the front. That's on an 8.5. So on the 9.5 youd be at 6.5 BS (ish) to be comparable.

On the rear, with a factory width early axle on a super low static / bagged setup I would suggest a 22x10 wide wheel with 5.5BS. On an 11, 6.5BS. 12 wide 7.5BS

I usually do 20 all the way around. Nothing against 22, I just like a little more sidewall. Theres a link in my signature, check out the last few posts of my gold 68. That truck is 20x8.5 with 5 3/8 BS. 255/45r20. 20x10 in the rear with 5" BS. 295/45r20

If you notice in my suggestion I mentioned the 22x10 with 5.5BS. It's just because I feel like your truck is lower that where I usually run them. Most gius I know that are bagged run 6" BS on a 10 in the rear. But you have more room for tires,.. so if you go wider than a 10 I'd put it toward the inside. (More)

I'd definitely check to make sure you have the early axle too. If you lay under the truck and measure from the inside edge of one brake backing plate over to the same spot on the other side, the early axle is 55.5" long. The later one is 57" using this measurement. It can mean the wheels working or not.

Good luck with it man.

[Jason Banks]

I concur with CC69Rat.

I have a 1968 with the narrower rear end and 20x10 wheels that have 5.5 inch backspacing and I'm going to need spacers to keep them from rubbing the inside of the bed wheelhouse.

If you have the wider rear from mid 70 and later the 5.5 backspacing on a 20 inch wheel would be fine.

I did also go with the 295/40r20 for the rear tire. It's got a sidewall height similar to the 255/45r20 front...

[SkidmoreGarage]

A suggestion, that worked for me, is buy the wheels you want from summit or jegs. They have very generous return policies and will accept wheel returns, and have free shipping. You can mount them up with a template of your desired tire (I used cardboard) and move everything around to check fitment.

These trucks are all different, all wheels are different, and all tires are different. It's very hard to do something custom and not have to just try. The good news is that there is quite a bit of room under these trucks, the wheels just have to be in the right spot.