Dealing with a difficult tranny leak. The shop is going to take it out and reseal everything. They said they would do the rear main seal also IF it's a one piece seal. Apparently GM made a two piece seal and then changed to a one piece. The two piece are very problematic and difficult to replace etc. so I'm trying to find out if my 1971 lemans sport 350 has the one piece rear main seal or the two piece. Does anyone know what it has or when the change to one piece took place? Thanks.