I have a 1966 F-100 that I want to put a set of new rims on. I have done a little research on what backspacing I should have, and I am getting all kinds of different answers. I want to go with a 15x8" rim, tires 235x75R15. Some say 0 backspace is needed some say 4.5. What to get the rims ordered and on the way to my garage. Here is my build thread 66 F100 Market Place Build - Ford Truck Enthusiasts Forums (ford-trucks.com)
Thanks!

 

I have 15x8 all around with 235/75 on the front, wheels have 4" backspacing. Don't know of any wheel with O backspacing!!



https://ok4wd.com/blog/the-differenc...d-backspacing/

 

We checked out your build thread on the truck. That's a good find.

Regarding wheels and backspacing. With a 66 2WD F100 that has the stock 5 x 5.5" bolt pattern, you could go with anywhere from 3.75-4.5" of backspace on a 15 x 8" wheel. On an 8" wide wheel 4.5" of backspace is considered 0 offset which would center the wheel on the hub. The lesser the amount of backspace the more the wheel would stick out from the truck. The same holds true for offset. Here are all of the 15 x 8" wheels we offer in a 5 x 5.5" bolt pattern in that range of backspacing. Some of those such as the Bart modified or stock car wheels are non-DOT. Obviously, you don't want to go with any non-DOT-approved wheel.

Here's some helpful info on wheel backspacing and offset. The third link down is a chart which is a helpful tool to show the relationship between backspacing and offset.
- Backspacing
- Offset
- Backspacing to Offset conversion chart

Your planned tire choice of 235/75-15 is a good choice as well to fit a 15 x 8" wheel and your truck. Let us know if we can be of any further assistance.

 

Thanks for all the help. That clears up what I was looking for on the backspacing. Placed an order for rims and tires this afternoon.
Again thanks!

 

Just for the fact that we have Summit Racing repped here on FTE makes me SO glad I've spent piles of money with them on my truck!

 

Nice looking truck for sure.

 

Yeah, Backspacing and offset are two paths to measure how far in or out of the fender your tires will be in relation to the mounting surface/brake hubs, if a wheel has a "deep dish" (old style terminology) construction, it can be and usually is negative offset. Positive offset is your typical front wheel drive wheel, with the majority of the wheel width towards the inside. Wheel width measurement is from inside to inside where the bead of the tire meets the rim. Backspacing takes in to account the thickness of the metal that makes up the rim, which is how you end up with an 8 inch wide wheel with zero offset having equal amounts of width going in and out from the hub mounting surface, approximately 4.5 inches.

Important factors when going with non stock wheel sizes... making sure there is no contact from the wheel or tire with any suspension & brake components, and clearance with body panels, full turn left to right, along with vertical travel as the suspension is compressed or extended.

Once you choose the wheels that work best for you, also make sure you have the right lug nuts for the new wheels. The conical surface for a taper seat lug nut needs to match the wheels properly. The shop I worked at had more than a few guys that were having issues with their lug nuts becoming loose because they tried using their stock lug nuts with the wrong taper / conical angle.

 

very nice truck Jeff and thanks for that explanation Chaos and Order
steve

 

Thank you for the excellent response to the backspacing question. I went with the Vision 148 rims 15x8" with the 3.75 backspace.
Can you recommend the proper lug nuts for this type of rim please?
Again thanks for the information.
Jim

 

I just did a new tire/Rim replacement on my 64 f100. I ordered 17x8 wheels all around with all having 4.5 backspacing. . They fit and function on the truck perfectly, BUT! I felt the rear set up was to inward. I put on 1.5 spacers in the back and it’s perfect. No rubbing front or back.

 

There are two basic styles of wheel spacers, the first being simple shim plates with holes for the wheel studs to go through... typically these are the thin spacers ( 3/4" or less ). The other style resemble wheel adapters with 5 holes for the factory studs to bolt on to, and 5 wheel studs mounted in the spacer to bolt the wheel on to. With either type of spacer, you need to ensure that you're getting enough of the threads of the studs engaged in to the lug nuts. a good rule of thumb is, the threads of the wheel stud needs to be fully engaged in to the lug nut (a few threads extending out past, with an open ended acorn lug nut. I've also been told that what ever the stud diameter is, that's how much thread you need to have engaged to keep everything secure. With shim spacers, this may require installing longer wheel studs.

With the adapter style wheel spacers, once the stock lug nuts are holding the spacer on, you must check to be sure the factory studs & lug nuts are not preventing the wheel from mounting flush to the spacer/adapter plate. Sometimes grinding the original studs flush is required.

 

Jim,

Thank you for your patronage! You've received some great additional info and advice from the community. We did want to clear up which wheels you purchased before looking into lug nuts. It looks like Vision wheels only offers the 148 series in a 4.5" backspacing for a 5 x 5.5" bolt pattern. From the info we have a 66 F100 2x4 should have a 5 x 5.5" bolt pattern. Let's clear that up and then we'll move onto lug nuts.

 

No thank you for chiming in and supporting our cause. We all appreciate the knowledge and welcome the advice. I did purchase the Vision 148 Shift 4.5 backspacing 5 x 5.5 bolt pattern rims.

 

No problem. We're happy to be a part of the FTE community!

Those take a 60* conical seat lug nut. For the 1/2-20 studs on your 66 F100, you would want a closed lug nut around 1.5" long. Here are the options we have that would work for you. If you wanted to stick with an open lug nut you could go with any of these. We'll get subscribed to your build thread so we can follow along with the build!

 

Thank you for following along and with tech support on products. I did get a chance to get the tires and rims put on this weekend. As you can see in the picture the center caps on the front will not go on. The dust caps do not allow for the Vision center cap to push on. Do you have any suggestions? or is there another cap that can be used that is a little deeper?