Drain Plug Snafu

Okay here goes. Needed some extra drain plugs for my new to me Mercruiser 3.0. The guy at the boat store sold me draincocks cause they were a whole lot EASIER! The drain hole in the block has a 1/2" brass fitting that screws into the block that the 3/8" brass plug screws into. Well of course, I sheared off that 1/2" brass fitting trying to take it out to install the 1/2" draincock. After an hour of gut wrenching contortion I was able to get the old plug to thread back into the brass threads left in the block. I checked it with muffs and no leaking. I go back to the boat store and get a 3/8" draincock to put back in the brass threads left in the block. I try to put the 3/8" draincock in but it's crossthreading the draincock threads. So I stopped and put the old plug back in (checked it, no leaks). Cause I'm going to the lake tomorrow if I have to weld the damn hole closed and drill it out later! So my question is THIS WINTER should I buy a 3/8" NPT tap & die and try to clean up the brass threads that are still in the block, try to get the 3'8" draincock in, then LEAVE IT ALONE. Or should I drill out the brass threads and tap the iron block for a larger draincock?

Re: Drain Plug Snafu

None of the above.
You should remove and replace the brass bushing with the mucked up threads.

Re: Drain Plug Snafu

I don't think I'm going to be able to get the brass threads out without some additional mucking up. Upon closer inspection I see red loctite on the brass threads. Think a 1/2" NPT tap will cut the brass threads out without messing up the threads in the block? That would be great.

Opps, Put this in the wrong place. Sorry.

Re: Drain Plug Snafu

Not likely, thats really hard to do being the tap has to match up exactly and begin the thread at the precise moment, the brass bushing should come clean from the cast iron block, the brass is sometimes too soft for easy out so you just pound a stubby screwdriver into it and if that don't work, you end up digging it out little by little until the threads just collapse, I know you probably don't have much working space and it's easier said then done, definately going to be a project, at least for now you have a good bandaid.