[mockingbird812]

Mikey, I agree. I don't understand why there would be a different tag (and for that matter the trans construction) for a L34 vs L78 engine in front of an M21. Referenced car is original engine, tranny, and rear with owner history and multiple dealer and factory docs. What could matter (as far as differentiating M21 variants on the assembly line) is the speedo gear wrt the rear axle ratio.