Sorry, I thought I had replied to this one earlier on in the week, but I can't see my post there so not sure what happened.
First of all, check the dimensions of your shackles - the MU ones fit a Hilux and vice-versa, but they may not fit the Bounty. You may need to make them from scratch.
Secondly, if you're not carrying heavy loads you could experiment with removing certain leaves from the pack - but just be aware I won't be able to return them for any warranty claims once the packs have been tampered with - I've already discussed this with Maxitrac since I'm running modified Hilux rears in the front of the MU. Having said that, I'm happy enough with the quality of these springs to run them modified.
I'd pull the third leaf out first of all, see how that goes. Also possibly the base overload leaf (the shortest one) to try and get it to flex a little better. Just be aware you may get axle-wrap and/or poor load carrying ability by doing this.
Experiment with leaf removal - its the only way to find out what works. Its time consuming and a PITA but short of doing a falcon spring conversion on it I can't think of a better way
If you want some drop shackles made up you would have to take photos and accurate measurements of the plates, pins, etc first - Mumads ones may be able to be modified to suit, or you just may have to start from scratch...
Hope that helps
Steve
Steve