I'm so confused? what 5speed do I have????
 

About 2 months ago I finaly got an other 240Z.
I had been about 6 years without one, and found a good running 72' with a straight body, and good overall condition, But one of the prior owners has done all kinds of work to it that I need help to decipher.
My Z now has a 5speed trany. and I believe a R200 Diff.
On top of the bell housing is stamped 78-16994
is this the model number, or S/N?
if so what do I have? if not where do I need to look for the ID?
also where on the diff. is the Id plate?
I've taken a quick look but found only an oily film covering both the trany. and diff. (just thick enough to make it imposible to find any stampings!)

"why do we drive on parkways, and park on driveways?"