Wheel/ Tire Combo

[jmartinezi@msn.com]

I have a 67 C10 with stock rear/ front end components. I plan to add 2/4 or 3/5 drop to it and add 20 x 9.5 rally wheels. I would like to see what wheel/ tire combo will not rub?

[Jason Banks]

Can you post a link to what wheel you are going to use? We need to know the backspacing and offset to get you close.

My go to with 20's on a 10 inch wheel are 295/40R20. But, the backspacing is important. It's highly likely you will need a spacer.

[Hawkynz]

I am running 20x10 rear and 20x9.5 front with drops. Rear tires are 295/40R20 and front is 245/45R20. The rear is about max width I would run. I have about an inch both inside and out from the bed. The front will rub on the fender if you autocross it aggressively, but not bad.

[jmartinezi@msn.com]

Wheels: 20 x 9.50 offset 20, BSM (in):6.08

https://www.visionwheel.com/wheel/47...5%2D2983GMML20

Tires: 245/45R20 103Y B BFG (Front), 275/40R20 106Y B BFG (Rear)

[jmartinezi@msn.com]

Hawkynz, did you need spacers?

[Jason Banks]

I would bet the wheel would rub in this situation. 6.08 inch backspacing is too much.

You can take off a rear wheel and measure from the inside surface of the wheelhouse to the front surface of your rear drum(or disc). It is probably not 6 inches(or very close).

Look at this thread:
http://67-72chevytrucks.com/vboard/s...d.php?t=646815

Post 5 - jmking9 has the wider rear end than you do. By .75 inch. He say she has 5.95 backspacing on 9.5 wide wheels and it is very close to rubbing.

For the narrower rear end this equates to 5.95 - .75 for a total of 5.2 inch backspacing almost rubbing. There's lots of threads on this. I found one where I said for a 9.5 wide wheel one the narrow dif, 4.25 might be maximum backspacing.

[jmartinezi@msn.com]

So would I need spacers in a situation like this?

[weq92f]

.

With stock '67 12 bolt, running 20x9.5, 5.5 offset, I needed a spacer to keep from rubbing inner fender/bed. The drop is 4/6 or so.

-klb

[LS short box]

Pic of my 68. 4/6 drop.
285/40 and 255/40. 9" Rambler wheels in the back. 8" in the front.

[Jason Banks]

LS Short Box. I looked at all the Rambler wheel diameters and only saw wheels that are 9.5" wide except the 22" and your don't look like 22's. Which one exactly do you have?

20X9.5 5X127 5.29backspace
18X9.5 5X127 5.29backspace
22X9 5X127 5.04backspace - But those sure don't look like 22's

Another thing. Are you positive you have the narrower 1968 rear end? i had a 1968 but swapped in a 1972 rear end so I could fit off the shelf wheels easier. I had a US Mags wheel that was 20X10 5X127 5.54backspace and with 295/40R20 it was so close to rubbing. Your tires look like they are just as far out as mine were.

[Jason Banks]

Originally Posted by jmartinezi@msn.com

So would I need spacers in a situation like this?

Best bet is to measure. But I bet a 1 inch spacer would get you real close...

[HalfBrit]

If you wind up using spacers, US Wheel Adapters make a quality product. I have 1/2" hub centric spacers on my '70 C10. Here's a link:
https://www.uswheeladapters.com/

[CC69Rat]

I usually do a 4.5/6 drop

On a stock 67 rear housing I do a 20x10, with 5" backspacing. 295/40r20. 295/45 will work, but it's tight.

On the front, 20x8 or 20x8.5. 4.5 or 4.75 backspacing. 255/45r20.

*The critical thing you want to measure the rear housing. From the inside edge of one rear brake backing plate over to the other side in the same spot. If this measures 55.5", you have an early rear housing (before mid year 69) if the measurement is 57" you have a later rear housing and the specs above won't work.

If it's a late housing, I do a 20x10 with 5.5" - 6" backspacing. It just depends how low you drop your truck.

*** everything above assumes you have a fleetside truck. If you have a stepside, it's completely different ***

Hope this helps.

[CC69Rat]

4.5/6 - static. Square body front Kmember. (85 Silverado F44 1.25)

20x10 - early housing. 5" BS. 295/45r20
20x8.5 - 4 3/4 BS (if I recall) it has been a while. 255/45r20