68-70 8 3/4 rear into a 72 Charger

[72Charger]

Hey, I can't find anyone who has done this kind of thing before but will you guys take a look at my plans and tell me either if it will work or not or am I just not thinking clearly.

First off, I have a 72 Charger with a 8 1/4 rear end in it. I just did a 318 to 440 swap. (if anyone ever wants to do this...dont! Just Kidding.... It wasn't to terrible)

I'm on a really tight, almost nonexistant, budget so I recently got new wheels but instead of the 4.5 - 5 inch backspacing I wanted because it would have costed several hundred dollars more, I got wheels with 3.25 inch backspacing.

Ok here is where I need your help...
    I want to run a 275/60 tire in the rear giving me a semi-wide looking stance. My problem is that my new wheels will stick out farther than the wheels I wanted. Here is a link to the look I'm shooting for. http://71superbee.com/Andy_Guevarez/image_04.html  These wheels have a 4.5 inch backspacing and they're close to the quarter panel so I know with my backspacing I'm going to have problems.

My options are (1.) go up... Jack up the rear and get a rake look. I like this option partly because I like the look but the major downside is that I don't want the tire sticking to far out of the wheel well and I don't want the tire to hit the quarter panel on a large bump.
                                                                                                       and/or
                     (2.) narrow the rear end... I want to replace my rear now to a 8 3/4 and an earlier (68-70) rears are 2.8 inches narrower so that would bring in the rear 1.4 inches on both sides.
                 
Am I just not getting something or would the narrower rear (1.4 inches narrower) and my new wheels (3.25 inch backspacing) act like a car with the correct rear and a wheel backspacing of 4.65 (1.4 + 3.25)?

Now I know I would have to move the leaf spring perches but thats not a problem.... I think.... Just grind them off and weld new ones on right?

I'm sorry for such a long post guys. Please tell me if this is worth a shot or any problems you might think of. I'll take any advice anyone has to offer.
Thanks guys,
    Ben

[firefighter3931]

Ben, that 68 b-body 8 3/4 will work fine....spring perches will have to be relocated which is no big deal. That swap was covered a few years back in one of the Mopar mags...they needed a narrower rear end housing due to the wheel backspacing they were using. Going off memory, the car was a 71 Charger and they were using torque thrust wheels with 3.5in backspace and a 275/60/15 tire and it worked quite nicely.



Ron

[kamkuda]

I did similar on my  Cuda.  I swapped a 66 Charger rear to get the rims to work.  (My error in ordering/incorrect backspacing)
Easy swap and the 8 3/4 is a good upgrade from the 8 1/4  Just get the pinion angle correct when welding on the new perches.

[72Charger]

 
Guys like you are exactly the reason why this website is the best.

Thanks for the input!

Oh... is the pinion angle somewhat the same in every b-body or is it car specific?  I'm just trying to figure out if I can just grind off the old perches and put new ones on at the same angle as the old. Make sense?

[RD]

i would say they are different due to the different lengths of each vehicle involved.  It is best to go ahead and put your housing in with loose perches, adjust the pinion angle, then tack the perches to the housing tubes.  that way you know you got it right the first time.  but, this has been the only way I have done it, someone may chime in a say that its not necessary.

OR

you can just put it in and adjust the angle using shims too.

[firefighter3931]

Oh... is the pinion angle somewhat the same in every b-body or is it car specific?  I'm just trying to figure out if I can just grind off the old perches and put new ones on at the same angle as the old. Make sense?

Ben, with a stock or heavy duty leaf spring the ideal pinion angle will be 3-4* nose down. If you're using a superstock spring and will be racing the spec changes to 6-7* nose down.

Jamey's idea of tack welding the perches with it in the car works very well and will save you the hassle of having to use shims. 



Ron

[72Charger]

Thanks guys!   

I never really thought about putting it in with loose perches and tack welding it to get it right even though it makes alot more sense than trying and hit or miss.

I'll give you guys an update and hopefully some pictures soon...

Thanks,
   Ben