Hotchkis suspension

[Bobbydodge]

Would it be counterproductive to use the USCARTOOL leaf spring relocation /mini tub kit along with The Hotchkis suspension TVS kit?

[Chryco Psycho]

The spring relocation only moves the springs inboard a couple of inches , obviously the wider the springs the better the effect but it is a minor change , the biggest issue is the rear sway bar , you either have to bend it or work an offset link so IMO no reason not to do it as the wider tire would compensate .
If you are talking about moving the front spring mount 3-4 inches in board into the frame rail  & cutting the wheel tubs this is more of a drag racing mod & would be less beneficial to a handling car .
Having said that I ran ladderbars in my Duster , this turned the axle housing into a 3" diameter rear sway bar , I could often lift the inside wheel off the ground in corners !!

[HP2]

Moving leafs in reduces their effective rate approximately 10# per inch of relocation. In other words, it does impact them some, but probably not enough for most drivers to really notice.

[1 Wild R/T]

The hotchkiss rear sway bar is axle mounted & attaches to the inboard frame rail so moving the springs inboard but still outside the inner frame rail won't effect the bar at all....

How much tire are you trying to run?  Dr Diff offers bolt in kits that will gain you 1"- 1.5" per side that's enough for a 13" wide tire, to use what the US Car Tool kit gives you you'll need mini-tubs & can likely fit a 15" wide tire..

[gzig5]

The hotchkiss rear sway bar is axle mounted & attaches to the inboard frame rail so moving the springs inboard but still outside the inner frame rail won't effect the bar at all....

How much tire are you trying to run?  Dr Diff offers bolt in kits that will gain you 1"- 1.5" per side that's enough for a 13" wide tire, to use what the US Car Tool kit gives you you'll need mini-tubs & can likely fit a 15" wide tire..

Dr. Diff only does the 1" model now.  That allows you to drop in a 65-70 B-body rear end with no other changes.  E body spring perches are 46" spacing and B body is 44.  The older ones are narrower flange to flange too.

Tables show the various dimensions
https://www.bigblockmopar.nl/tech/mopar-rearaxle-dimensions/