B Body 8 3/4 in 71 Demon

[zac_F71]

Hey guys looking to put a uncut 69 Road Runner 8 3/4 axle in my 71 Demon - what back spacer wheels are needed and has anyone every done it?

Parts I have -

69 RR housing
68 Cuda 3.23SG 3rd member (probably change gears to 3.73/3.91)
68 Charger stock axles
15x8 w/ 5.5" backspace Weld Prostars w/ Nitto 275/60 NT555R's (drag radials)

I know the spring perches need to be moved inward and that will be done along with the MP offset spring shackles/hangers (professionally at SharaDon's in Hugo MN)

BUT does anyone know the wheel specs to fit up in the stock wheel well - rolling the outer lip is cool with me if it needs it to fit..

Thanks

 

[Bad Sport]

The 5.5" BS should work just right. I have the B rear in my Sport with that backspacing and it's perfect.

Here's what it looks like. No rubbing or any other issues. My wheels are 15x10 with the 5.5 BS.

 

[zac_F71]

Awesome! Got any close up pics of the wheel/wheel well relationship?

I'd go mock it all up in my car now BUT my garage is 25* and the floor is even colder I'm sure- being not heated sucks..

 

[goldduster318]

This is pretty close to what you'd get:

'68 B-body axle with the MP offset shackle kit and those at 225/60-15 on 15x7 with 4.125" backspace. So with the same setup and 275's on a 15x8 with 5.5" backspacing, your tires would be 5/8" more to the outboard side. 6" backspacing is probably better, but you can probably get by with it.

 

[Brad4406]

71 Duster with B-body Dana, 10" Weld Draglites w/6.5" backspacing, springs relocated 3/4" inboard. No tub and never a rub. I'd post pics, but that computer crashed and the car is long sold.

 

[zac_F71]

This is pretty close to what you'd get:

'68 B-body axle with the MP offset shackle kit and those at 225/60-15 on 15x7 with 4.125" backspace. So with the same setup and 275's on a 15x8 with 5.5" backspacing, your tires would be 5/8" more to the outboard side. 6" backspacing is probably better, but you can probably get by with it.

that's exactly what I'm going to run so they should clear with a roll of the fender lip just fine! Thanks guys this is a HUGE help!

 

[72bluNblu]

I have a 68-70 B rear (54 15/16" flange to flange) in my Duster with a hanger/shackle offset kit. Currently I've got 15x7 cop rims with a 4.25" backspace and 225/60/15's. No rubbing, but I wouldn't go any further out toward the quarter. I've got almost 3" to the springs, so about 2.75" of useable space on the inside.

For a 275 on a 15x8 I'd be looking for minimum 5.75" BS, up to about 6.25" of backspace. At 5.5" of backspace you're probably going to have to trim the quarter lip to keep it from rubbing unless your springs set the rear up high.

 

[zac_F71]

Well will see it will all be mocked up here very soon.. (as soon as my 2 fox mustangs are gone)