Attn: Wheel and Tire Pros

[ipaintem]

I am currently building a 71 C10, I will be running Foose Injectors, 20X12 in the rear and 18X8 up front. My question is backspacing. The rear is bagged and C notchec with a 3" mini tub. The front has a Scotts Rod Shop IFS with rack and pinion and McCaughey's 13" big brake kit. No bags, coil overs and dropped spindles. The front track measured from the face of the rotors is 63". Im pretty sure I can get away with running a 335/35 on the back on a 20X12 with 8.5" of back spacing. But the front is where Im stumped. 18X8 with 4.5 back spacing "should" work but I really dont need a $2000. set of end tables. WHat do you guys think?

You can see pics here at my hub garage.
http://http://www.hubgarage.com/mygarage

If the link doesnt work, go to Hubgarage.com and searh JMC Autoworx

[68Lowrider]

On a stock width front i run 4 3/4 back space and its perfect I ran a 4 1/2 first and it rubbed the inner fender well lip when aired down . On a 20 by 12 with 8 inches of back spacing you must have a wide rear end I run 10s with three and they are 3/4 of a inch from the inner lip with any reasonable rear end width I would think 5 inches would be close with a 12 inch wheel, Are you measuring your back space from the inside out? Mitch

[SCOTI]

Originally Posted by ipaintem

I am currently building a 71 C10, I will be running Foose Injectors, 20X12 in the rear and 18X8 up front. My question is backspacing. The rear is bagged and C notchec with a 3" mini tub. The front has a Scotts Rod Shop IFS with rack and pinion and McCaughey's 13" big brake kit. No bags, coil overs and dropped spindles. The front track measured from the face of the rotors is 63". Im pretty sure I can get away with running a 335/35 on the back on a 20X12 with 8.5" of back spacing. But the front is where Im stumped. 18X8 with 4.5 back spacing "should" work but I really dont need a $2000. set of end tables. WHat do you guys think?

You can see pics here at my hub garage.
http://http://www.hubgarage.com/mygarage

If the link doesnt work, go to Hubgarage.com and searh JMC Autoworx

71 rear housings are slightly wider so I feel your rear spacing is good & it should pull the wheel in enough to keep it off that outer fender lip w/o being too much (over tucked looks just as bad as leaving them hanging out in the open IMO). I ran a 20x10 w/a 6"bs on my 68 w/slight trimming of the inner bed floor necessary. Add 2" to that & it would be 8"bs for a 12' wheel. Now consider that your housing is slightly wider (approx .750" per side) & that 8.5" works.

The front sound good too. The SHR front set-up has a narrowed track width vs. OE 67-72's. Many guys run 8" wheels w/4"bs w/o issue. Your choice of a little more back-spacing coupled w/the slightly narrower track width should again keep the wheels off the fender lips.

As w/any big purchase, you really should mock up a known wheel combination & verify that the numbers will work. I used what I know (standard 15x8" 4"bs steel ralley) to do the 'reverse' mathmatics on your proposed combo. Even if it were mine, I would be hanging a wheel & double checking the numbers.

[68Lowrider]

Wouldnt it look better to have the front wheels with a different offset than the rear looking at it from the front with the math provided above the front and rear would end up 3.5 offset looking at it from the face ? A 12 inch wide rim and a 8 inch wide rim on a 68 thru 72 truck looks nasty with no wheel stager

[SCOTI]

Originally Posted by afuel7067

Wouldnt it look better to have the front wheels with a different offset than the rear looking at it from the front with the math provided above the front and rear would end up 3.5 offset looking at it from the face ? A 12 inch wide rim and a 8 inch wide rim on a 68 thru 72 truck looks nasty with no wheel stager

If the track widths were equal. The SHR front end sucks the track width in so w/an 8" wheel 4-4.5"bs will keep the wheel off the arms & off the sheetmetal. If you opted for more back-space, it would possibly be sucked in pretty far combined w/the narrowed track width. I ran 18's w/5.25" on OE track width. Subtract the 1" difference for the narrower front & you're @ 4.25"bs.

If you wanted a deeper dish in the rear (which I agree does look better), you'll need a narrower rear end (which would require swapping to a pre-70 housing, narrowing the current rear, or swapping in a shorter housing from a car), or the wheels will need to be closer to the fenderlip (which can compromise how low you can go because of interference).

[BCOWANWHEELS]

I JUST MEASURED FOR some wheels and 4 1/2" back spacing is all that would work no matter where, front or rear.

[SCOTI]

Originally Posted by BCOWANWHEELS

I JUST MEASURED FOR some wheels and 4 1/2" back spacing is all that would work no matter where, front or rear.

What did you measure? Did you take into consideration he listed a different front suspension & the fact that he's got 3" mini-tubs? That makes a difference on what works & where.

[68Lowrider]

Scoti correct a 70 and up the rear and front are the same width i did see he has has a narrowed front of approx 1 inch . I would like to see 2 inches narrower in the front and would def. recomend switching to a pre 70 or ford nine inch to fill those tubs up with a deep dish rear wheel. One inch stager will still look straight up.

[SCOTI]

Originally Posted by afuel7067

Scoti correct a 70 and up the rear and front are the same width i did see he has has a narrowed front of approx 1 inch . I would like to see 2 inches narrower in the front and would def. recomend switching to a pre 70 or ford nine inch to fill those tubs up with a deep dish rear wheel. One inch stager will still look straight up.

From what I remember on N2Trux's old Blazer (which has a Scott's front end), the track width was pulled in 1" on each side vs. stock.

[68Lowrider]

Correct per side....

[ipaintem]

So we agree that a 20x12 with 8.5 and 335/35 will look best for the rear?
For the front, should I go 3.5 bs because of the narrowed front? Or maybe go to a 9" wide wheel to fill up some of the lip on the outside?

[ipaintem]

Are you basing the front being narrowed 1" off of my measurements or off the Scotts front end? Because I did switch the Scotts spindles over to the McCaugheys spindles and they are MUCH bigger than what the Scotts came with. The 63" measurment is what I have now with the McCaugheys spindles on the truck.

Just making sure we are all on the same page.

[lolife99]

ipaintem,...
why don't you bolt on a set of 15x8 inch wheels front and rear. (with NO tires)
Then get out the tape measure and see where everything fits and looks good. Add 4" to the rear wheels to simulate a 12" wide rim. The 15x8 truck ralleys have a 4" bs,... so you can calculate off of that.

[SCOTI]

Originally Posted by SCOTI

....As w/any big purchase, you really should mock up a known wheel combination & verify that the numbers will work. I used what I know (standard 15x8" 4"bs steel ralley) to do the 'reverse' mathmatics on your proposed combo. Even if it were mine, I would be hanging a wheel & double checking the numbers.

^^ I agree ^^ . . ....

[lolife99]

Man SCOTI,...
I gotta start reading these threads closer. Ha.

[jbristo67]

You should just run 20s all the way around

[ipaintem]

I dont have the bed and fenders on as of yet. I was thinking that at least the rear could be a pretty definite yes or no on what would work.

The front I do have a 15X8 to check for clearance and I will do that tomorrow.

thanks

[ipaintem]

the owner wants 18's and 20's