You don't replace seals on BB turbos ,, change the chra.. get the char for the 28rs or 2860rs and change the compressor wheels from the HKS to it ,, then you have the HKS 2530.
Installing the SZ-exp90 now in fact it's in the car but I would wait for the new revised kit which includes the air duct tubing.. which is not a part of the kit now..Just spoke to Seb about it last week..