Rear spring change effect on diff angle

[Righty]

I'm interested in peoples opinions on this. So I have just swapped out the old leaf springs and put ESPO HD +1" springs and new KYB Gas a justs on all round on my 69 Barracuda, its a 318 with the stock 8.75 axle. I also fitted a set of adjustable front hangers from Uncle Brians as although I want a bit of height over stock I dont want too much The height from floor to centre of the wheel arch satarted at 26.25" and its up at 28.25" now. (a quarter inch higher on the LH side). The old springs were as flat as pancakes, so 2" lift seems about right to me for brand new springs with 1" extra, although it is higher than where I want to end up. The shackles are pretty upright at the moment so i'm hoping as the springs settle out they'll tip back a bit more and I'll be closer to about 27" at the arch.

Obviously the difference in ride quality is night and day, I havent lost a single filling since! But I would say the car tramps about a bit more over roads that have a lot of directional undulations from trucks etc and the other concern I have is wether it has maybe introduced a bit of a shunt at low speed, so from standstill or rolling to pulling off there is a feeling of taking up the slack in the driveline from the back end of the car.
I wonder what peoples thoughts are regarding driveshaft to pinion angle with the increased ride height would I be sensible to lift the front bushing up in the adjustable hangers and drop an inch or am I overthinking and just let the springs settle in and drop of their own accord?

 

[TheGrateRonzini]

Well, I would say that your stock location rear end perches would keep your angle of the housing as it sits on the perches at stock ride height is ideal, right? Well how far off do you think you actually changed it from where it would sit factory fresh. At what point of deflection would you say it needs to be changed in lieu of premature failure? Measure where it is at now and where you think it will end up once settled and then decide with that information. I don’t think you need to worry about it, but once you have the data, you can base your decision on that

 

[Righty]

Of course I should also have measured the original wheel centre to arch lip height to compare to the new, as that would give me the true change in the distance the centre of the axle has moved down relative to the wheel arch.
So reverse engineering it, taking in to account tire deflection 15.5" of the 28.25" new floor to arch lip height is from the wheel centre, so applying that ratio to the original floor to lip height of 26.25" ride height gives an original centre to lip of 14.25" which would indicatethat the new springs have pushed the axle down (or the car up depending how you look at it) by about 1.25". So I would hope that would settle to the 1"+ of the ESPO springs.
The other factor of course is although changing the front bushing to the next hole up in the adjustable hangers will lower the overall ride height, because the distance from the bushing to the axle is relatively short by lifting the front end of the spring I would in theory be tilting the front end of the diff up even more. I guess if I really want to check this properly I'll need to check the angle of the diff to the prop and the solution would be angle shims. Maybe for the moment I'll assume I'm fine.