MGA Propshaft Tech covers that otherwise gaping space between the gearbox and the rear axle. This is one small assembly, but there are some design variations, and there can be some very serious problems.

PS-101 - 3 PROPSHAFTS used in the MGA.

PS-102 - The BAD U-JOINT - when to be SCARED.

PS-103 - os - Propshafts and U-Joint Alignment.