68 Dart post. Narrowing a big car rear end to fit. If you had a choice for width would it be exact a body width (accounting for b body brake diff) or narrower for wheel choices. Also using 1\2" offset kit. Not really planning on cutting car. ?
cutting rearend anyway
- Thread starter ohiobill
- Start date
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Depends entirely on what wheels you want to use. Typically, if you want to run wider 15's you want A-body width or narrower, while if you want to run wider 17" or 18" rims you probably want wider than A-body width. That just makes it easier to find off the shelf rims in those sizes.
My suggestion would be to pick the wheels you want first, then figure out how wide the rear axle should be to put them where they need to be.
My suggestion would be to pick the wheels you want first, then figure out how wide the rear axle should be to put them where they need to be.
pishta
I know I'm right....
save some money and cut it to A-body axle length so you can use those. If custom axles and 1/2 offset, Id go maybe 2 inch shorter on each side.
DoctorDiff sells custom length axles for $5 more than A-body length axles, so it’s not really much money you’re saving.
And if you have to get custom wheels to get the right backspace to work with the A-body width, you’ll be losing money.
If you’re going to go custom, you might as well pick the width so you can buy the wheels you want off the shelf with whatever backspace they come with. That might save you money, and it might mean being able to use the wheels you really want, vs something that will fit that you don’t hate.
pishta
I know I'm right....
So for $300 you can get any length you need new. I was speaking about saving money by buying used A-body axles in a 5 on 4 pattern and making a stock A-body 8.75. If guy wanted to use B-body brakes (did I read that right?) custom wheels , by all means go with the 5 on 4.5 axles cut to length, then he'll have 2 bolt patterns on his 68 car minus BBP disk upgrade.
Right, he's using B-body brakes. So, 5x4.5", and no stock axles unless a C-body or truck set is getting cut down. In which case, custom length still doesn't matter.
And we have no idea if he still has SBP brakes on the front, especially since we already know he wants to use B-body rear brakes. Probably already ditched the SBP up front, since that makes sense. Or maybe he doesn't care about dual patterns. Either way, stock 5x4 A-body axles won't work with the brakes he's planning on using on the back, so if you're buying or shortening axles already you might as well get exactly what you want for wheels and go from there.
Thanks guys. Yes, I'm going to run bbp discs up front. I've done some more research and I think i see now what I need. The answers in post #2 is my dilemma but also what I needed to hear. So I think I will have rear built to stock width. I'm going to run 'cop' wheels with drag radials when stick shift drag racing and 17x8 5.25 bs wheel with spacer TBD for everyday handling road wheels.
What size tires are you thinking?
Ive read some of your info from other threads and if I can run 245/45/17 all the way around I will start there. I do have two TT 17x8 4.75 bs with that size tire on them now and they measure almost perfect on the back but if they are going to tear up the front fender I will look to the bigger back space. It does prove the small spacer for the back.
Move springs to frame rails if you want some bigboy tires.............
pending your wants/needs.
pending your wants/needs.
Sounds about right!
Yeah I think you’ll need 5” of backspace to clear 245/45/17’s in the front. The 5.25” should be perfect.In the back, if you have a 7.25" in there now with the 17x8's and a 4.75" backspace keep in mind that the 7.25's are not the same width as an 8 3/4. And the difference in width to an A-body 8 3/4 with BBP brakes is a little over a 1/2". So, you will probably find that the 5.25" backspace is pretty close for a BBP A-body width 8 3/4 even with the stock location springs. With the springs moved in a 1/2", you won't need a spacer at all.
Right, but then you need a mini-tub as well. With the stock wheel tubs and a 1/2" offset most Dart's can run a 275 in the back. Wider than that takes a mini-tub, and there's no point in moving the spring unless you do the mini-tub. The 1/2" offset gets you all the space you can use with the stock tubs.
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