Rear welch plug aka expansion, core, freeze plug

XK-Engine
1

Can anyone tell me the size of the rear welch plug above the bell housing on an XK140 engine?

I know the side ones are 1-3/4", but the rear one is larger.

Thanks,
–Gary

2

It should be the same size.

3

You’re correct. I knew there was one plug of a different size but it’s on the RH side, not the rear.

Thanks,
–Gary

4

1", IIRC. The plug seals the passage where the oil drains from the rear of the head back to the sump so no pressure behind it.