Another 700R4 Question

[GlennBrittain]

I have the 700R4 installation complete, with the exception of my tempature gauge. My problem is a leak at the rear tail shaft seal. My transmission builder, a buddy deal, said my front yoke does not go far enough into the transmission. I did measure the distance with my old transmission and with the new transmission installed. The measurements came out to be the 3” noted on several Internet sites on the subject. What I do not know is was the driveshaft the proper length to start with, since the previous owner pulled out the standard and installed the turbo 350.
Does any know what the distance the yoke should be inside the tail shaft? I would like to resolve that issue before replacing the seal. I plan to put my truck back up on stands, scribe the yoke at the seal the drop the driveshaft to see where I am at now. Unfortunately, my tractor is calling me to mow first and it is 101 degrees here today.