some 4/6 drop wheel help (yea i know)

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86Peter454

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so im in need of some new wheels.

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ill be doing a 4/6 drop on the truck as well.
the plan is mcgauphys 2.5 drop spindles. (1" rotors im 99% sure)
1.5 drop springs from western chassis
then just a flip kit in the rear no notch.

i would like to stick with 15 inch wheels if i can but most say you will have to do some trimming on the lower control arm (i dont want to do that for fear of making them weak) if you get the wrong offset.

i willing to go up to 17s if i have to.

what offset would i need? if 15x8 would a 4" backspace work up front? then if i went with 17x8 would a 4.5 backspace work? or will i need to go down to a 7in up front with like a 3.75 backspace?

i know this has been talked about a lot and it seems most either stick with 15s and trim the control arm or go up to 20s and that is way to big for my style. so just not sure what route i should take.

any help is much appreciated.
 

Jrgunn5150

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I'm just in for info, I'll be doing the same and I also don't like 20's
 

86Peter454

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well not sure how much info we will get lol. 135 views on this thread and youre the only one who replied lol.


i found a set of 15s i like. so i would run 15x7 with 3.75 backspacing up front and a 15x8 with 3.75 back spacing in the rear. anyone know if that would fit?

squarebody syndicates "formula" uses same drop spindles i plan on using (though 1.25) and they use 15x8 with 4in BS and 15x10 with 5in BS in the back.
https://www.squarebodysyndicate.com/sbs-formula.html

they make no mention of needing to clearance things but from what i can tell stock rallys are 15x8 with 4in BS and many people need to clearance those. idk maybe grinding on the lower control arm is not a big deal? am i wrong in thinking that will weaken them too much?
 

animal

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Jrgunn5150

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well not sure how much info we will get lol. 135 views on this thread and youre the only one who replied lol.


i found a set of 15s i like. so i would run 15x7 with 3.75 backspacing up front and a 15x8 with 3.75 back spacing in the rear. anyone know if that would fit?

squarebody syndicates "formula" uses same drop spindles i plan on using (though 1.25) and they use 15x8 with 4in BS and 15x10 with 5in BS in the back.
https://www.squarebodysyndicate.com/sbs-formula.html

they make no mention of needing to clearance things but from what i can tell stock rallys are 15x8 with 4in BS and many people need to clearance those. idk maybe grinding on the lower control arm is not a big deal? am i wrong in thinking that will weaken them too much?

I'm not far enough to look seriously yet, but I'm not personally shy of clearanci the control arm a bit.

I have a full set of stock steelies as of today I intend to use, which is going to limit my tire size a bit, I can live with that.
 

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Seems like McGaughy dropped spindles will cause the lower control arm to hit the rim of a 15x8 wheel, depending on the wheel's backspacing. In fact, I just now remembered that a McGaughy's employee confirmed it. That's why I went with Western Chassis dropped spindles on my 82 C10. They clear 15x8 Rally wheels by 1/4" or more. And the castings and machine work were first rate.
 

86Peter454

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Seems like McGaughy dropped spindles will cause the lower control arm to hit the rim of a 15x8 wheel, depending on the wheel's backspacing. In fact, I just now remembered that a McGaughy's employee confirmed it. That's why I went with Western Chassis dropped spindles on my 82 C10. They clear 15x8 Rally wheels by 1/4" or more. And the castings and machine work were first rate.

what is your rotor thickness?

any chance that would effect the control arm clearance between the 1.25" and the 1"? just a thought.

ill look into western chassis spindles as an option.
 

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I ordered CPP spindles and plan to run the original truck rallies. I am still a bit far from trying them though. I also have a set of van rallies that I could run up front if that helps. I will be sure to take pics when I get around to putting the wheels on but just got the spindles this week and I still need to replace the bushings, clean, and paint stuff before going back together with it. Could be a few weeks or months before I know if the CPPs will be trouble.
 

86Peter454

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well i just ordered all my lowering bits today. (mcgaughy 2.5 spindles)

i also did order a set of wheels. they have 3.75 backspace in front and back. 7in up front 8in in back. ill be sure to update this once i have it all installed that way others can see what kind of clearence i get. hell these may not fit either idk lol.

im with you travis it could be a bit. i too am replacing bushings and plan to paint and clean up while im in there.
 

RangRayy

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I asked this very question and found info for 17s. I’ll try and dig it up.
 

Rusty Nail

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I always thought that if 15s didn't clear the front, all one needed was a ****** little spacer, like 1/4"?
Maybe then a little grinding?

16s will fit almost everything but sometimes there is a rear fitment issues with a 14 bolt , for sure with 15s..

More than 4" backspace pushes the wheel past the fender out front?
4.5" is too much?

But if you dont have 30 (1ton) brakes, I don't recall most 16s havin other fitment reqs..I THINK that has something to do with 17s being required, but don't quote me.

On that.

Actually don't quote me on any of that **** but it's probably right.

If you're going to buy NEW wheels 16s is a good choice but I wonder if 17" tires are cheaper??:shrug:
 

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