I decided to get an ATI superdamper and it landed yesterday (order by Summit). The damper includes a crank hub and it is special version for LT1 gen II SBC (Corvette C4 92 - 96 model). I had to hone the crank hub to get it on. With the damper installed I could also install the serpentine belt system.
The diameter of the ATI superdamper is 7.530" and diameter of stock damper is just over 7". The stock serpentine belt is to short. As shown on the pictures the drive belt tensioner is not part of the system with stock serpentine belt. Stock belt is 67 or 68 in long. I have measured inner length of new belt to be about 69 in. I probably need a new belt which is close to 70 in long. I will try a couple of belts and check the marks on belt tensioner to find the correct length.
UPDATE 1 : finding a correct length serpentine belt with ribs on both sides is difficult. Stock length is OK to find but slightly longer is not easy. 92 models and early 93 models Corvette C4s used serpentine belts with ribs on both sides. GM issued a "1992-1993: Service Bulletin: Noisy/Fraying Accessory Drive Belt " and converted those cars to serpentine belts with ribs on one side only. I´m converting my serpentine operation to single sided belt. Three wheels needs to be replaced. In picture below serpentine belt should be routed on-top of "idle wheel" which is wheel on the right side of belt tensioner.
UPDATE 2: I´ve got a TPIS A/C pulley delete landing tomorrow at home. I will try to replace some of the wheels with overdrive wheels to make stock serpentiner belt fit. I will either convert to single sided belt or stay stock length serpentine - but A/C is deleted in both solutions ;-) Much cleaner engine bay and another bonus is shedding of some weight.