oem wheel width?

[hiball3985]

The Ebay ones say 4.25 back spacing, will that work?

[RICH MUISE]

Thanks Lynn....awesome...I just checked Ebay yesterday morning!! I'll try to call them to make sure it's actually in stock and not being drop shipped. Yeah,Jim, same backspace as what I've got now.

[RICH MUISE]

They do not stock them...they were going to have it drop shipped from Rocket...Thanks anyway, Lynn.

[lalessi1]

Bummer... I thought it was worth a shot.

[gasman826]

.....have 3/8 clearance to the fender inner lip at the backside/top of the opening....

I've watched this discussion with interest.  I have a couple of cautions that have not been mentioned.
1) since you are test fitting a new wheel/tire combo, you might want to test fit on both sides of your car.  Differences are not uncommon.
2) 3/8" is NOT enough clearance.  Leaf springs (even with the extra wagon leaf) with rubber bushings will allow the rear end to shift more than 3/8" in curves and cornering.  The bigger, front sway bar may help, rear sway bar may help, poly bushings may help but 3/8" will disappear and your new paint will get scorched and your new tires will be scuffed.  If you change your suspension to a triangular 4-link with heims joints or solid bushings, 3/8" is enough.  If you change to 4-link with panhard bar with heims or solid bushings, 3/8" might be enough.  I know these are bold statements but wheels, tires and paint are to expensive to have to replace due to inadequate clearance.

You have also mentioned the possible future rear disc brake upgrade.  The rotor is almost an 1/8" thicker than the brake drum.  So now, you have 1/4" clearance.  Some rear disc brake conversions require a .250" (1/4") spacer added between the axle bearing and axle bearing flange.  This space pushes the axle a 1/4" closer to the fender.  Now you have no fender/tire clearance.

How do I know...one of my '57s has 3/8" tire/fender clearance with triangular 4-link.  10k miles and no tire scuff on the sidewalls.  My '57 wagon is OEM with 3/8" clearance and every corner the tires rub.  At highway speeds, by the end of a curve, I smell smoke!!

[RICH MUISE]

Hey Gary....good to see you posting again...I was wondering about you for awhile.
I checked my body for centering a long time ago when I was remounting the body, and it is pretty close, but it will get checked again. That 3/8 is actually not to the fender lip itself, but to the flange of the inner wheel well. When I rebuilt the wheelwells, I made the new flanges a little wider. End result is the same of course, but should I need to trim a bit, it'll be easier.
One of the last biggies on my list is the rear end. Aside from 3.50 trac-loc and disc brakes, I was planning on narrowing each side 3/4...maybe I should go to an inch per side.
The other consideration now that I know I don't have a big problem with getting the tire on/off, is not converting to discs. The main reason for that was more clearance...but in some respects, as you mentioned, there may be less clearance (or at least different...dia's vs length, )

[lalessi1]

Gary, that is great info. When I first got my car, It had 15x7, 4.00 B.S. on the rear and 14x6, 2.75 B.S. on the front. I swapped them around (to see how far out I could move the rear wheels) and the tires rubbed on the back on one side in a corner, even at very slow speeds. Rich, I can BARELY put my rear wheel tire combo on my car now with the shocks attached (225/60, 15x7, 4.25 B.S.). You may want to double check that while you wait on your wheels or plan rear brakes or rear end narrowing.

[RICH MUISE]

I had also planned on using '5655 shocks, as Jim Nolan is, which allows the axel to drop down further than a '57 shock.
I guess the only reason I wouldn't narrow and change to discs now is for the cost savings....so it probably will all get done eventually.

[lalessi1]

Very interested in the shock thing. I have Gabriel Hijacker air shocks now, wondering what a modest extension might do. I haven't tried disconnecting the shocks to put the wheel/tire on. Seems I remember jacking the rear end up to fit the shocks...For me at this point rear discs and/or narrowing the rear end are way down my "wish list" as well.

[RICH MUISE]

Not way down on my wish list...It's next on the list...just waiting for some $ to do it. After I get tires for the two 6" wheels that were delivered today, I've got to pay some attention to new rear springs, shocks, (front and back) I've also got to find out from Pat Fleischman who it was in Lubbock that he uses for all his differentioal work, and try to get a cost nailed down on that. I don't know if he can supply the trac loc and discs, or if i need to start picking up the components. I'll continue my looking for a rear already done the way I want just in case somebody actually has one for sale.
Jim..btw, you asked about the 4 1/4 backspace..... which is fine for the back, too close for the front if you have the Concorse sway bar as I do. The 6" have a 3 1/2 bs which should be just fine. Now I've got to figure a tire size for those so I can get them on order.
Lynn...here's a link to Jim's shock thread:
http://57fordsforever.com/smf/index.php?topic=2674.msg15175#msg15175
Not sure if just an extension on the '57 shocks would work...i wouldn't think so.

[hiball3985]

I think I get the back space thing mixed up. My Cragars are 3 1/2 or 3 3/4 I forget, and they barely go on so I guess the 4 1/4 moves the wheel closer to the spring?

[RICH MUISE]

Not sure I could have answered that a month ago,...same with tire sizes. I just didn't pay much attention till the time came when I had to know. LOL...I even now know the difference between offset and backspace.
The short answer...Yes, a bigger backspace will move the wheel closer to the spring.
You know I gotta give a long answer........from what I understand, offset is a European thing and the dimensions are usually given in metrics. For all practical purposes, we don't really need an offset measurement, but for the record....offset is the distance from the center of the wheel to the mounting surface of the wheel. Positive and negative offset dimensions are determined by whether the mounting surface is inward or outward from the wheel centerline. From there you can do the math to add or subtact the offset to 1/2 the outside width of the wheel to determine backspace. Frankly I don't remember which way the neg and pos dimensions are, but as I said, most of us won't care...it's alot of calculating when you can just use the given backspace dimension. I'm sure there are alot of suspension/handling gurus that want to know where the centerline of the wheel is.
Backspace is the distance from the mounting surface to the outside of the back rim. It is not to where the tire mounts...which is where wheel widths are dimensioned. (a 7" wheel actually measures about 8" on the outside)
So....combining everything mentioned, if you had a 7" wheel with a zero offset, the backspace will be 4". As I said, no need to even be concerned with offset for most of us...I just included it in the discusion because I see guys using the term when they really are talking backspace.

[lalessi1]

Positive offset moves the wheel inward and reduces the track width. Negative offset moves the wheel outward. Negative offset increases spring loads (on the front) and bearing loads and increases steering effort. The center of the "contact patch" of the front tire is a point used in suspension geometry design, moving it affects the handling of the car.

Rich, good info on the shocks, thanks.

[Ford Blue blood]

Rich give the 95 - 01 Explorer rear a hard look.  They are 59.5" wide.  Shortening one side to center the pinion, using a second short axle from the same year would probably come in close to even on cost.  Many many Exploeres came with T-lock.  3.55, 3.73 and 4.11 were available ratios with 3.73 the hardest to find.  They have an easy to hook up emergency brake system and the best part over the counter parts for years to come.

[RICH MUISE]

I'm gonna copy your post and start a different thread on that. I'll do it in the General Tech board since we've got seperate boards for engines and trannys, but not one for the 3rd member.
I've probably got a bunch of tire size questions coming up for the front for the guys that have had issues with tire and ground clearance problems with the HD sway bar/dropped spindles.