I've got two 833 4 speeds, one has a C-99127 tailshaft and one has the B/E type C-99538 tailshaft. from what I'm told they'll both work in a 70 B body but the transmission mount is a few inches different between the two, I don't have the engine in the car so I can't measure it and I don't want to rebuild the wrong one. anyone know which one is correct?