Oil gallery plug size?

[Talkwrench]

What's the thread size for the rear oil gallery plug? I drilled out the brass plug as far as I dare go and I've tried to pick out the remaining but someone must of used some super sealant 'cos I can't shift it. I'm hoping I can pick up the threads and cut the remaining out...

 

[51 MERC-CT]

Don't know about rear plug but front plug on 8BA is 3/8-18 NPT that uses a 37/64" drill size.

 

[marko39]

It should be 1/4 inch pipe thread. Mark

 

[Brian]

yep; 1/4 NPT

 

[Talkwrench]

Cheers, thanks guys!