Need opinions please

[Steve Cole]

I need some last minute advice on wheels. I have already decided I want 18" wheels, not 20's. because I have a '68 step side with the narrow rear, my rear wheel widths are limited. My two choices are 18x8" all the way around or 8" in the back and 7" in the front. Because I have front disc brakes, my front wheel track is wider than the back by about 3" (roughly) so I was thinking a 7" wheel up front would narrow my track a little so the front will be closer to the back. A 7" wheel has a backspace of 4.25" and the 8" rear is 4.5" so does that mean the front will be closer in by .75" per side? Or should I just stay with 8's all around? BTW, I was going to run a .25" spacer in the rear to give a little cushion.

Thoughts? Suggestions?

[Steve Cole]

I guess I'm just wondering how much I'm going to gain if I run a 7" front vs 8" all around.

[NC_John]

run bigs and littles Steve.

[Fitz]

I guess I'm just a pig because I ran17 x 8's in front and 17 x 10's in the rear on my 67 stepside. They are a bit bigger than the stock 15's!

[Steve Cole]

Originally Posted by Fitz

I guess I'm just a pig because I ran17 x 8's in front and 17 x 10's in the rear on my 67 stepside. They are a bit bigger than the stock 15's!

Hi Fitz, what backspacing did you use on the rear? On my truck, 4.5" looks like the max I could run without spacers.

[Steve Cole]

Anyone else?..

[bs46488]

Steve,

What kind of tire sizes are you thinking?

[Steve Cole]

Originally Posted by bs46488

Steve,

What kind of tire sizes are you thinking?

Originally when I was planning to 18x8" all around, I was going to use either a 255/50/18 or a 255/55/18. Currently I am running 255/70/15 and if I try and keep the same tire diameter then I would need a 225/60/18 in the front (if I went to a 7" wheel) and a 255/55/18 in the rear. That would put me real close to my current diameter of 29.04"
The problem is, I haven't found a tire company that sells both needed sizes. Also, I don't know if I will achieve enough "tuck" in the front to make it worth paying more for the tires and losing the ability to rotate my tires.

[Gimme Jimmy]

When you buy your wheels be careful to check the offset. I would be inclined to
use wheels with about 1/2" (13mm) Positive offset. Avoid using negative offset as it will require much more steering effort, and may be difficult to align.

[Fitz]

Originally Posted by Steve Cole

Hi Fitz, what backspacing did you use on the rear? On my truck, 4.5" looks like the max I could run without spacers.

Steve:
I used the same backspace Stacey David did on Copperhead. 4.5 in in front and 5 in in rear.

[bs46488]

I see what you're looking to do.

I did the 7" tire on a project and the tire shop was a real pain about what size tires "fit" the rim.

I would try to keep them all the same so that you could rotate them. But I would buy 17" tires. And you can fit like a 255/60-17 and have some tire choices

[Steve Cole]

Originally Posted by Gimme Jimmy

When you buy your wheels be careful to check the offset. I would be inclined to
use wheels with about 1/2" (13mm) Positive offset. Avoid using negative offset as it will require much more steering effort, and may be difficult to align.

Hmmm, thanks for the tip. All the wheel and tire threads on this board and I have never heard that mentioned here before. Could have been a costly mistake.


Fitz, did he use spacers? My wheels with 4.5" BS leaves about .25" to the bedsides. I must be doing something wrong.

[Fitz]

Originally Posted by Steve Cole

Hmmm, thanks for the tip. All the wheel and tire threads on this board and I have never heard that mentioned here before. Could have been a costly mistake.


Fitz, did he use spacers? My wheels with 4.5" BS leaves about .25" to the bedsides. I must be doing something wrong.

Steve:
Copperhead didn't use spacers and I didn't use any either. Is your truck a fleetside or a stepside? I took measurements earlier this year because I'm going to tub my 67 stepside to get wider rubber under it. Here's the dimensions from frame to outer fender lip, frame to wheel mounting face and inner bedside to the frame. From those dimensions you can get the offset you need to fit. I have about 0.5 inches between the inner side of the tire and the bedside on a 285-60 x 17 mounted on a 10 inch rim. I'll take a wheel off tomorroe and recheck for you. This is a critical measurement and it's really expensive if you don't get it right. It just occurred to me. I picked 10 inch rims because I want to run either those 60 series Proxes S/T street tires or 14 inch wide M&H slicks because they have the same overall diameter but those street tires would be a little happier on a 9 inch rim.

[The Camaro Guy]

I run 255 x 45x 17/9.5" R & 235 x 50 x 16/8" on my 69 SWB, lowered, no problems

[Steve Cole]

Originally Posted by Fitz

Steve:
Copperhead didn't use spacers and I didn't use any either. Is your truck a fleetside or a stepside? I took measurements earlier this year because I'm going to tub my 67 stepside to get wider rubber under it. Here's the dimensions from frame to outer fender lip, frame to wheel mounting face and inner bedside to the frame. From those dimensions you can get the offset you need to fit. I have about 0.5 inches between the inner side of the tire and the bedside on a 285-60 x 17 mounted on a 10 inch rim. I'll take a wheel off tomorroe and recheck for you. This is a critical measurement and it's really expensive if you don't get it right. It just occurred to me. I picked 10 inch rims because I want to run either those 60 series Proxes S/T street tires or 14 inch wide M&H slicks because they have the same overall diameter but those street tires would be a little happier on a 9 inch rim.

Hi Fitz,
Mine is a stepper as well. I will pull my wheel today and get some good measurements and pics. Just by looking at it, it appears to have about .25" clearance from the inner tire to the inner bedside. From the outer tire to the fender lip I easily have 1" of clearance. Maybe because I'm currently running a 15" wheel with a 70 series tire? Once I switch over to a lower profile tire, I'm sure I will gain a little extra clearance. I measured my wheel track and it looks like the front wheels stick out almost 1.75" per side wider than the rear wheels do. My thinking was I could run a 7" wheel in the front which should tuck the front .75" per side and an 8" in the back with a 1" spacer. I don't like the idea of spacers but this should bring the wheels back in line with each other. What do you think?

[Steve Cole]

Originally Posted by The Camaro Guy

I run 255 x 45x 17/9.5" R & 235 x 50 x 16/8" on my 69 SWB, lowered, no problems

Hey Camaro Guy, 3 questions for you: 1. Is your truck a step side? 2. what is your back space on the rear wheels. 3. do you have the narrow rear end? Thanks.

[Fitz]

Originally Posted by Steve Cole

Hi Fitz,
Mine is a stepper as well. I will pull my wheel today and get some good measurements and pics. Just by looking at it, it appears to have about .25" clearance from the inner tire to the inner bedside. From the outer tire to the fender lip I easily have 1" of clearance. Maybe because I'm currently running a 15" wheel with a 70 series tire? Once I switch over to a lower profile tire, I'm sure I will gain a little extra clearance. I measured my wheel track and it looks like the front wheels stick out almost 1.75" per side wider than the rear wheels do. My thinking was I could run a 7" wheel in the front which should tuck the front .75" per side and an 8" in the back with a 1" spacer. I don't like the idea of spacers but this should bring the wheels back in line with each other. What do you think?

The front track as set by the factory was 63.1 inches and the rear was 61.1 inches. I wouldn't try to change it because I just don't think it's necessary. If you are in a club try to get them to buy a wheelrite wheel and tire simulator. It bolts right up like your wheels and allows you to adjust diameter, section width and offset. It's 99 bucks so even if you have to buy it and use it only once it's a lot cheaper than buying a second set of wheels. Just ann FYI...most of these specs can be found on oldride.com.

[Steve Cole]

Thanks Fitz, good to know. Does the factory measure track from the centerline of the wheel bearings or the centerline of the wheels? When I measured mine, I put a straight edge on the upper and lower outer tire sidewalls and made a mark on the floor off the straightedge. My measurements were 77 7/16" in the front and 73 3/4" in the rear. This equates to 3 11/16" difference front to rear, or about 1.75" per side. I pulled the rear wheels today and measured the face of the brake drum to the bedside and it was 6". Then I measured from the drum face to the fender lip and got about 6.25". One thing I discovered today was the 255/70/15 tire I'm running has 1.25" of tire overhang per side, this explains why my tires are rubbing on a 8" wheel with 4.5" backspace. Because of the tire, it's more like 5.75" backspace. Is there a chart somewhere that tells how much tire bulge you get from the different series of tires?

[Fitz]

Originally Posted by Steve Cole

Thanks Fitz, good to know. Does the factory measure track from the centerline of the wheel bearings or the centerline of the wheels? When I measured mine, I put a straight edge on the upper and lower outer tire sidewalls and made a mark on the floor off the straightedge. My measurements were 77 7/16" in the front and 73 3/4" in the rear. This equates to 3 11/16" difference front to rear, or about 1.75" per side. I pulled the rear wheels today and measured the face of the brake drum to the bedside and it was 6". Then I measured from the drum face to the fender lip and got about 6.25". One thing I discovered today was the 255/70/15 tire I'm running has 1.25" of tire overhang per side, this explains why my tires are rubbing on a 8" wheel with 4.5" backspace. Because of the tire, it's more like 5.75" backspace. Is there a chart somewhere that tells how much tire bulge you get from the different series of tires?

Now you've got me. It would seem reasonable to measure from the wheel mounting face to mounting face because the track width changes with wheel offset but you could argue that the measurement must be made when the suspension is loaded and at ride height. I simply do not know.