rear end measurement

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New Member
Dec 16, 2005
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i'm having a hard time deciding what measurements to give for a custom rear end for my tubbed '65
i want to be able to have a set of drag wheels, maybe 13" width or so, but also be able to bolt on some street tires, maybe with a 10" width and have them both be in the correct position and look good.
is there any way to bridge this big of a gap with offset or spacers, or anything else?
bear in mind, i do not have the rear end or the wheels yet so everything is customizable
thanks,
Matt
 
No problem, get a center offset or maybe a bit positive with the drag wheels and get full reverse with the street rims. Keep in mind, the deeper the offset, the better it looks and the easier to change. My buddy has a '55 Crown Vic with 15" wheels and he has to disconnect the coil overs to drop the rear down enough to take the wheels off.

If you can, it would be best to get the street wheels and tires first, then set them under the car where they look good and don't rub throughout the full range of travel, then take the flange to flange measurement off that, then you can order the drag wheels with the extra offset to the inside.
 
You can't postpone the rear end build? You can do it right once or you can do it wrong at least once and maybe more times.

The only other thing I can tell you is to make a template. A 13" wheel will be 13" wide from where the bead sits, so the wheel itself is really 14" wide, i.e. a 10" wide rim is 11". Figure out what tire you're going to use and see what the sidewall width is when mounted on your rim. Don't forget to take into consideration that a slick will grow in diameter as you go down the track if you're running slicks. Make two templates and lay them under your car where the footprint will be and measure the distance where the flanges will be. You should be able to get what backspace the manufacturer will make.

The other thing you could try is to work backwards from the stock rear end width for your car, if it's a '65-'66 it'll be 52 1/4", then it's just math.

I just hope your not in over your head, don't put the cart before the horse.
 
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do i atleast have the theory right on this picture, with these offsets and backspacing, would this 14 in rim and this 10 in rim stick out exactly the same from the wheel hub?
i am not a wheel expert, but if someone could evaluate this and let me know if this is hypothetically possible i will have somewhere to go from
thanks, matt
 
I curious why 2 different sizes. I would rather have smaller ones on the track. More tire than you need will only slow you down. Your street tires are the ones that are going to spin. What size tires are you planning on?
 
I curious why 2 different sizes. I would rather have smaller ones on the track. More tire than you need will only slow you down. Your street tires are the ones that are going to spin. What size tires are you planning on?

the track tires will prob. be 30x16.5-15 slicks, and the street tires, maybe 305/30-18 or something like that.
matt
 
The tires are about 5" different in hieght. Gearing will be tough. When you put the slicks on the effective gear ratio will take a blow. That tire is overkill IMO. There are guys going 7.0's @ over 200 mph on 28x10.5 slicks. There are also guys going 5.60's in the 1/8 on a 26x8.5, which is around an 8.70 in the 1/4. Are you looking for Pro-touring on the street and Pro- street on the track? If you cut the quarters for 30" tall tires, it will look awkward with 25" tall street tires.