Trying to figure out backspace on my front wheels

[Screenem]

I am trying to figure out the backspacing for my front wheels... I am thinking of a 22X9 for the front with a 5" backspace. The truck has a Porterbuilt level 2 touring, bag suspension. I want the wheels to tuck nicely, but I would also like to have a larger lip without steering issues. Does anyone have a photo of this wheel size or similar with this backspace? Any help you can offer would be greatly appreciated, thank you!

[jbice70gmc]

bump

[CC69Rat]

Welcome to the board from TN

At this point there are a few questions:

Are you planning to use an aftermarket inner fender? Or inners at all? (I am assuming you will)

Do you know if the PB drop member is stock track width (the width from one front wheel to the other as if the truck was on a train track. Is it stock width or is it narrowed? Some of them pull the track width in a bit, also your front spindles (CPP is known for this) will narrow the track width too. Some drop spindles will widen the track width .. it just depends on which ones youre using.

I can tell you, the 22x9 on a 5" BS will not work unless you have one of the items above narrowing the track width a bit and/or lose your inner fenders. On the stock track width, bagged without inner fenders (or Slosh Tubs / trailers, etc.) I would go with a 5.5" BS on an 8 or 8.5" wheel.

My best and highly suggested solution for you is to build the truck like you want it. Bag it, body drop, etc. all you want to do .. THEN measure for your wheels. Buy your wheels to fit the truck, Dont fit your truck to the wheels you bought. Make sense?

My 68 is a static 5.5/7.5 right now with a 20x8.5 and 5 3/8" custom backspacing. 73-87 Kmember, Stock inner fenders, and it's rubbing. Just imagine a 22" wheel about 3/8 or 1/2" further out than mine( adds a total of around .75" more to the outside )

It has probably been done at some point, but in my experience the wheels youre on wont be a good choice unless your DM changes the track.

Hope this helps

[harpo231]

Hey cC didn't forget ya ,,just upholster guy dodgin me...looks like you gettin help

[jbice70gmc]

Well since this thread is basically 3 years old I don't guess the original poster is still looking for this info. I have a 69 GMC with the original rearend and the front is all stock except for the CPP modular 2.5" drop spindles and the front disc. I'm going with the AZproperformance 14" rotors that are 1.1" thick. The truck is also on bags with a mini C-notch. No drop member. I'm ordering my Racelines in the morning. 20X12 W/5" of backspacing in the rear ( modifcations will be made) and 20X9 W/5" of backspacing in the front. It will have Sloshtubz installed. Just curious to know if the fronts will clear the outer fender. Of course if I have to I could always go with a 8.5" wide wheel with 5.25" of backspacing and add a spacer later if I fill like I have room to widen the front end. Any help would be appreciated. Thanks

[hewittca]

I'll chime in with an additional answer. I agree w/ CC in that you are going to rub with a 22x9 5" BS if you have stock width arms and stock inner fenders. I tested my truck at a 6" static drop up front with the stock trackwidth, stock inner fenders with 22x9 6" BS. I was very close to rubbing the inner fenders both in height and width. Imagine the picture below but in your case the wheels would be 1" further out. I had about 1" of clearance in width, so you would be rubbing without even any clearance to turn. I do plan on running my truck this low with the 22x9 6" BS on drop spindles which will push the trackwidth out another 3/4" per side. In order to run it like this I will have to modify the inner fenders. You can probably get your wheels to work too, but as CC said narrowed arms and/or modular spindles will be a must, plus modified inner fenders.

[BossHogg69]

x2 on what Chad (CC69Rat) & Hewittca said on the 9" wide fronts. I'm not running 22's, but I am running 19x9's and 19x12's. I'm running 6" backspace on front & rear with stock front inner fenders. Static drop - 5" front & 7.5" rear. It blows my mind how many people don't take the time to carefully measure for custom wheels before ordering! I was sweating bullets when I ordered my wheels, because it's an expensive mistake if your numbers are off. Yeah, getting on the forum and seeking advice helps, but with so many different aftermarket parts and setups available, there are a LOT of variables that can change things from truck to truck! Even a 1/2" difference will make the difference between your tires rubbing something or not.

[jbice70gmc]

Yes I agree that would be a very expensive mistake and I would definitely like to avoid that. I appreciate the advice and knowledge I have obtained here. I do have CPP modular drop spindles that should narrow the front end I believe. I also plan on some sloshtubz or some other sort of modified inner fender. Maybe 20x9 with 6" of backspacing would be ok.

[jbice70gmc]

I've read ALOT here and it looks like the majority is running 20x8.5" wheels with 5.25 backspacing that are on static drops and even some bagged trucks like mine. That should be the same as 20x9 with 5.75 backspacing correct? Also my plan is to run a 255/40 tire.

[hewittca]

Originally Posted by jbice70gmc

I've read ALOT here and it looks like the majority is running 20x8.5" wheels with 5.25 backspacing that are on static drops and even some bagged trucks like mine. That should be the same as 20x9 with 5.75 backspacing correct? Also my plan is to run a 255/40 tire.

Correct on the wheel specs there. You should be fine on the tire size. In fact, it will help you out compared to mine which is a 265/35r22 and 1.4" taller than the 255/40r20.

Also, did your truck have drum brakes to begin with? If so, the modular spindles only keep the same drum brake track width. They only narrow the trackwidth on trucks that were originally equipped with disk brakes.

[jbice70gmc]

Yes that is correct. The fronts were drum brakes also.