Iso Clamp removal... Am I missing something?

[Hilljack68]

I'm swapping out the 8.25 rear end in my 73 Charger in favor of an 8.75, and I'd like to delete the iso-clamps. I already picked up a '72 rear end. Instead of dealing with the mis-matched hole sizes on the perches/springs, couldn't I just source springs and shock mounts from a 71/72 Charger and be done with it?

I've read articles and posts until my eyes went all Marty Feldman, and no one has mentioned this as a possibility. Is there something I'm not taking into account?

(And no, I don't want to go Poly for the Iso-clamps; I just want them gone.)

Thanks guys

 

[QuickBpBp]

Yes. It's what I did with my RR. Except I had bushings made cause mine was a 73-4 8 3/4 rear so it needed them for the leaf spring/perch for the other leaf spring locator pin.

 

[Hilljack68]

Yes. It's what I did with my RR. Except I had bushings made cause mine was a 73-4 8 3/4 rear so it needed them for the leaf spring/perch for the other leaf spring locator pin.

So a 71/72 rear end with 71/72 springs should require no mods?

 

[QuickBpBp]

So a 71/72 rear end with 71/72 springs should require no mods?

I don't believe so just check you shock length I know I have switched those out but it's been awhile I forget what I ended up using.... Also I think they have a different front hanger as far as the bolt size in the front bushing..

 

[Hilljack68]

Yeah, I'll have to do a little digging. Thanks for the input.

 

[padam]

Yeah, I'll have to do a little digging. Thanks for the input.

I used mopar super stock springs when I changed mine over. I did have to put in shims to change the pinion angle. (Not to get this thread banned but I’d like to get rid of the springs.)

 

[Hilljack68]

I used mopar super stock springs when I changed mine over. I did have to put in shims to change the pinion angle. (Not to get this thread banned but I’d like to get rid of the springs.)

Oh crap, I didn't think about that... the pinion angle. Dumb question, but where did you have to shim it?... on the spring perch?

 

[padam]

Yes between the spring and the perch. Mine was off a mile, 7 degrees IIRC.
I made my own shims, so the pins worked out. I had a broken shock mount so I also made bottom plates.

My car is a Frankenstein lol.

 

[padam]

Undercar pics are from a few years ago. When I raced this setup I put old school shock extensions on.
The shocks are a plain monroe or something, probably the C-body shock mentioned in the DC manuals.

The shims I made on a CNC so I just milled the big circle on one side and drilled the hole on the other.

Usually when I make stuff I over build it.

I can't remember the year of the housing, it may have been a 71-72, so the center hole may have been different and why I had to make something special. I did all this in the late 80s.

 

[padam]

This is a little cleaner. Works better on the strip.

 

[Hilljack68]

Man, those are serious shims! Thanks for sharing - much appreciated

 

[padam]

Man, those are serious shims! Thanks for sharing - much appreciated

Yeah they might be 10 degrees

 

[padam]

Told you I tended to over do it, especially back in those days

 

[Nacho-RT74]

73/74 spring retaining studs are 3/8” with a hat shaped bushing to accomodate the isolation pad while 71/72 are 5/16” studs.

The 73/74 bushing on studs makes a step on the springs. I would remove those and replace the stud with a shorter piece. The bushing step could interfere with a correct seat of the axle pedestal over the springs.

 

[Hilljack68]

Told you I tended to over do it, especially back in those days

Hey, go big or go home.