WC and NWC both use ATF fluid. It is incorrect that gear lube will be an indicator
of a NON World Class (NWC) T5. More info on this and factory manual pages: http://www.allfordmustangs.com/forums/5-0l-talk/204680-tremec-t5-transmission.html
Your auto drive shaft yoke WILL fit the T5. The drive shaft will probably need to be shortened some to have ONE INCH
OF FREE PLAY. Too little and you can wreck your tranny or break the U joint and too much will cause vibration. Shorten/balance
and rebuild cost $150. CHECK IT BEFORE YOU CUT IT.
A T5 yoke has the same spline count but the part that slides into
the transmission is shorter. It does nothing for the 1 inch freeplay your driveshaft needs.
Consider using a T5 bellhousing
and the flywheel WITH THE CORRECT IMBALANCE so you can use a 10 1/2 inch clutch. you will also need a late model TO bearing,
clutch fork, late model starter and block plate
You can use the old bellhousing but you will need to modify it. You
will need a 2"x1"x1" aluminum or steel block and also the fulcrum (the piece the clutch fork pivots on) out of your early
bellhousing. Mustang suppliers sell it for about 40. You can then use your old clutch. You will also need to buy an adapter
plate to add the 1 inch the old bell will need to mount correctly
The T5 mounting bracket is needed because the the
mount is about 1 inch back and the old mount wont line up. I read of 1 person modifying the old one to get it to work but
he spent a lot of time doing it.