bypass spigot

[BSAA10Richard]

I am in need of some advice, I ordered a spigot for the bypass hose for the head from eBay which I believe is a mini one but also said Morris Minor, However it will not screw into the hole, it looks a little bigger, The thread in the head is good having managed to get the old spigot out without damaging it. any suggestions.
Also it looks like I will have to take the head to the machine shop to get Valve Guides fitted and seats recut, this is a 948 head, which valve guides do I need as ESM list two types one with a groove and one without, again they list two types of rubber seals for the valve stem, the ones I removed were just small o rings, which I cannot see what good they do, are the cap type that sit over the guide better? and can I fit this type.

[BSAA10Richard]

the spigot is in now, I welded a nut on top of the spigot then used locktight on the thread to give a good water tight seal and wound it in with a spanner,
I just need to know about the valves guides and seals

[philthehill]

The spigot is a 5/8" x 16 tpi UNS. It is not 5/8" UNF.

by-pass tap (1).JPG (1.13 MiB) Viewed 3747 times

If you have the right spigot it will screw in correctly.

BM bypass stub (2).JPG (1000.25 KiB) Viewed 3747 times

The valve guides with the groove for the top hat seal are the ones to fit. Use the shorter guides for the 948cc/1098cc.
The top hat seals need only to be fitted to the inlet valves so you only need 4 grooved guides. The small 'O' ring seals are next to useless and can be thrown away. Seals are not needed on the exhaust valves or guides.
However you get the new guides fitted you will need to cut/grind the seats centric to the new guide.

[BSAA10Richard]

Thank you for that, the spigot is in, it was difficult to start it but as my comment I welded a nut on the top of it and used a spanner then cut the nut off. The head will be going into a machine shop to be done but I will supply the ESM valve guides and use the top hat seals. Unless the phone call I took from a friend tonight led to a conversation about the engine and he has two spare heads also when asked if he had an engine knocking about the answer was " I may have" could my luck be changing?