Hello everyone! As you might assume by this question, I'm very new to hot rodding. I'm currently building my first and of course I picked an odd duck, much like myself. It's a '31 Pontiac 5 window. I've recently picked up a good '64 Pontiac rear (trying to keep it in the family or in this case the tribe). The original rear measured 50" flange to flange. The '64 measures 59 3/4", just a tad too wide to sit under the fenders! Anyone have a fool proof way of determining rear axle width? I'd like to fill out the fenders but keep the rubber under cover. Should I have the rear narrowed to the original's width? Any advice would be great!
With my '32, I put the wheel/tire combo under the fenders, adjusted them to where I wanted them to be, and measured from the inside flat of the wheel center to the other inside flat. That will give you drum face to drum face width. Subtract the width of the backing plate/drums, and you have what you need. To do this, you have to have the wheels with the backspace you will be using. Mutt
What Mutt says, but the only measurement that is relevant is the wheel mount surface to wheel mount surface. Backing plate flange to backing plate flange is apples to oranges as various mfgs have various width brakes. Charlie
That's the easiest way. You can do it with a tape measure and a little common sense but for a beginner Mutts way is by far the easiest.
OK I guess I need my wheels and tires. Just a standard backspacing and enough clearance for the drums? Looking to go with sheel reverse with moons.
Charlie Chops is right - don't know why I bothered to throw in the subtracting the drums when you're narrowing a complete rear. The measurement will tell you how much the tubes have to be cut. Now is the time to decide if you want a centered or off centered housing, too. With any luck, you can get by with only shortening one end and one axle, but it doesn't sound likely if you have to shorten 9+ inches. When you pick backspacing, use something that is common and readily available, so that when you need, or want, new rims you will be able to find the backspacing inexpensively. Make sure you have clearance on the inside between the body and tire - at least 1". Good luck. Mutt
The correct way to measure the width of a rear end is like this ... It eliminates all the guesswork and errors of brake drums widths, addition and subtraction ..
if ya have the rear end out from under the car ....i like to use a piece of 3" (or what ever fits ) exhaust tubing thru the center opening of the wheel....it will sorta give ya something to hold the wheels together ...and something to mark on ...like deuce roadster's picture shows.....measure a rearend this way .....waaaay to many variances in brake widths and offsets....did your poncho come from grant county ....?? or possibly someone in boone....brandon
Yea, I got it from Bud over in Claryville Campbell Co. Thanks for the lead Brandon! Bud seems to really know his stuff and he's got a lot of it! I guess I need to work on getting my wheel & tire combo now to do an accurate job of finding my axle width. If I measure mounting surface to mounting surface, I assume whoever narrows the rear will figure out the rest. By the way, anyone know where I can come up with a set of backing plates to fit this rear? I just started looking and looked on Ames last night. They have the brakes and drums but don't show the backing plates. That's another question. When I have this narrowed, should I see if they can weld on a different flange, one that will accept a more common backing plate and brake set up?
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