I just had the Belltech drop hangars installed since I too could not get the desired look or drop with the JLP drop shackles I used to have and as well felt that the TVS system wasn't low enough. The drop hangars were a big job - probably 6 hours - but I definetely got the look I was looking for.
However the ride is now only good until I hit a certain type of bump which causes a bottoming out. I thought perhaps my Bilstiens were the problem and had shock extenders installed today. Unfortunately there appears to be no change in this condition. I do give some of the blame to my 22" rubber which is of a significantly lower profile than my original 20" Goodyears. As far as geometry change is concerned, yes the pinion needs shimming since the driveshaft doesn't align perfectly to the rear differential and under hard acceleration and with a few of us in the truck I do get vibration ( the Belltech kit included 6 degree shims which by the way is NOT enough and it appears that I am going to have to get someone to custom make me 7 - 8 degree shims since no one seems to carry them and because it is not recommended that one stacks shims ).
That aside,I believe there is a geometry change in the spring itself since the belltech drop hangar causes the spring to have more of a "plowing profile" since it causes the front part of the spring to be attached to the frame higher up. I believe that this causes the spring to be more sensitive to certain types of bumps. From this point it seems that the only solution to the bottoming out that I'm experiencing, given that I want to retain the existing look or drop, is to have a c - frame installed which will give the rear axle about 2" more travel / clearance.
I am doing the research as we speak.
2003 Harley 2-tone
Kenne Bell, Dynatech long tube headers, Bossanni exhaust, JLP Ram air, Metco pulleys, Diablo Sport Flip chip, Predator, Large air exchanger, Thunder Pipe, Accufab throttle body, JLP balanced short block with forged pistons, con rods, ported heads, Crower Cams, large injectors, Densos, JLP Air Plenum, adjustable fuel regulator, Warlboro 255 fuel pumps, mass air extender, Diablo Sport Mafia, Electric rad fan, Cobra water pump, 2400 stall, 4x4 transmission oil pan, Lightning valve body, JLP Traction bars, 2"front drop, Belltech Drop Hangars, Hotchkis Front and Rear Sway Bars, Bilstiens, Clarion 5.1 Surround Flip screen with IPOD. Focal speakers with 12" rear console subwoofer and amp, 8 piston Brembo front calipers with 15" rotors, Baer rear rotors, Detroit 22" replicas, BF Gooderich G Force Tires, Keystone Shaker Ram Air Hood.
JLP Built
571.64 HP, 638.65 TRQ
With more to come.