The spinning torque gauge is indeed 99% of the time caused by water/moisture on the plug(the big one on the LH side going from engine to airframe). We also do not bring water close and since then no problems-the Arriel is not a engine that leaks except if something is wrong so more often than not there should only be dust and grass etc in the engine deck so no need to make it swim. Another area which does not like water is the NR plug on the RH side of the MGB-be careful with water as it often leads to the NR min/max audio not working.
Enjoy the ride! I am sure you will be wondring what the B3 is all about then.................