Technical Flathead merc crank plug question

Pulled the welch plugs out my merc craank and tapped holes for threaded plugs. Cant seem to tap the hole enough to get the plugs flush. Would this be an issue?

 

Did you use a bottoming tap?

 

3/8 npt pipe tap

 

It probably will not make any difference but if you want to go closer to flush, cut the tap shorter with appropriate sharpening. Then you can go deeper. I have done it more than once.

 

I would go shopping for a shorter plug instead. They are out there.
http://m.summitracing.com/parts/mor...9NEaj9yHshYSJXrsWjsjLGwVwQ8-MInyhVhoC4Z_w_wcB

http://www.autopartswarehouse.com/s...5CMAU3PE-kIHVVz51tWthsGUyws-C6Ix6QhoCSTvw_wcB

https://www.google.com/search?q=3+4...KHV25BeUQgjYIzQMwCA&ei=ou8bV7WeOsyEmwHd8paoDg

 

i'd be more worried about the balance if you not going to have it balanced than i would the plug sticking out.

 

Thanks for the help. Block and crank going to the machine shop monday. It will all be balanced

 

Near dead center of the crank balance will not be an issue