I have used a Fischer damper from Cliffords and also an ATI Super Damper. The ATI unit is for a small block Chevy and you machine about 1/4 of an inch off the "snout" so that it will fit closer to the timing cover but it works slick and I spin the motor hard. The ATI is nice because any small block Chev pulley will bolt right on. I used the one that fits flush against the damper. Good luck!