91tpi-zf

Does anyone know the stock thickness (from ring gear to friction surface) of the L98 (1991) dual mass flywheel? I have been told that the LT-4 flywheel is thinner. The reason I ask is that I am looking at a flywheel that would not fit on a LT-4 without causing the PP and clutch fork to grind. He said that he had to get the correct one for the LT-4 to prevent this (thinner one). I am trying to find out to prevent me from buying something that I cant use Thanks.