CaptainChrysler

I am sure it has been asked a lot, but.... I was wondering what the correct backspacing for a 16x8 wheel, on a first gen?

CaptainChrysler

Any ideas?

BearKiller

Take a naked factory wheel (no tire mounted) and lay it face up on a level surface.

Stick a ruler through the center of the wheel, such that it touches the level surface.

Measure the distance from the inside surface of the wheel to the level surface it is laying on.

This measurement is O.E.M. wheel off-set, meaning Original Equipment Manufacturer wheel off-set.

Any replacement wheel should have this same off-set, regardless of wheel width.

The added width of a wider wheel will be to the outside of the O.E.M. off-set, away from the truck-frame, and not toward the frame of the truck.

Any added negative off-set will lead to all kinds of clearance issues, such as brake-caliper/drum interference, tie-rod end interference, etc.

For best performance, always use O.E.M. off-set wheels.

HAMMER_DOWN

Negative offset will reduce interferance with brakes, tie rods, etc. because it pushes the wheel out and away from these components, positive offset will cause clearance problems.

Here's a great wheel/ tire size and spec calculator:

http://www.bigcustomwheels.com/rt_specs.jsp

KartRacer

You guys are measuring backspacing, not offset. Offset is the distance from the centerline of the wheel to the mounting surface, hence the pos/neg. Also it doesn't hurt to have a couple inch wider wheel that has a similar offset (not backspacing) than stock. A little more wheel on the inside won't hurt.

BearKiller

Most everything on the road has a tie-rod end right against the wheel-lip.

Also, brake-calipers just barely clear stock wheels.

I get into this, every day, when big-eyed kids want to put wrong wheels on various vehicles.

Jschlachta

Another thing to keep in mind is that the correct offset loads the weight ontho the bearings correctly. so if you decide to go from the stock 6" wheel to an 8" wheel you would want to have same offset, so 1" in and out from mounting surface. this is not always possible that is why you have to check the wheel or measure out from the stock wheel. most aftermarket wheels that I have seen are either 4 1/4" or 4 1/2" backspaceing. another not is that the alcoa wheels for out trucks are listed as 16x7" with 4 1/4 backspacing placing the centerline of the wheel 1/4" inward from the mounting surface.

CaptainChrysler

I am looking at 16x8's with 4 1/4 back spacing. Are these going to work? I would measure the stock B/S but it is currently a dually. If any one has pics of their rig and the wheel specs that would be great.

KartRacer

Mine are 16x8 with a 4.25" backspacing:

CaptainChrysler

Can't see picture.

BearKiller

Is it your intentions to mount SRW wheels on a DRW dually ??

I think more than just bolting on wheels will be involved.

The bolt-pattern is the same, and the wheels will bolt on; BUT, the fronts are going to stick WAY out there.

CaptainChrysler

I know, it will be un-dually'd. I have been looking for some time now, for a SRW, but settled for a DRW. I am trying to get the parts rounded up, so there will be minimal down time. If anyone has a SRW rear end, I am looking for that, too.

A_port93

4 1/4 or 4 1/2 i cant remember

Jschlachta

Here is a picture of my truck with the Eagle alloy wheels. 16x8 with 285/75/r16 BFG tires

CaptainChrysler

What backspacing though??