PART NO.  SPL.PAGE  DESCRIPTION                                                            
6K431    TC.A.13   Washer for plug -copper -(sump, engine, Twin Cam)
2H4685    TC.A.13   Plug for sump -drain -(sump, engine, Twin Cam)

The 6K431 part is a standard 3/4-inch copper crush washer, 3/4"-bore x 1"-OD (about 1/16-in thick before crush). It is used to seal the MGA Twin Cam engine oil sump drain plug (0.747 OD thread, when using the original alloy sump). It may be the only 3/4-inch copper washer used for any MGA.

May use 6K431 in place of:
Supersession(s): 2K4982; 6K431B; 324-650; 324-800; GUG705712GM

In particular:
2K4982 is the fiber washer used with the oil pressure relief spring cap nut (in case you don't like (2) fiber washers there).