Does anyone have experience with Delta Vee as a Bilstein shock rebuild/revalve service? A rear b6/hd killed a deal on my car, I run 550lb springs and would like them matched to that rate and maybe shorter the rear shafts to avoid a potential future blown shock with a standard HD replacement. As it is, I'll have to buy a new shock through tirerack and send the old in for a potential refund after inspection.