Freeze plug size in lifter valley. 428

[6s1640]

Hi all,

There are four open holes in the lifter valley that require a freeze plug. I measured them just under a half inch. Do they take an .500 inch freeze plug or something slightly larger?

I had a complete freeze plug kit with these four extra freeze plugs that I discovered I needed and no longer have. I can't find any size information on these four locations.

Please advise

Thanks

Cory

[pbf777]

    You'll need to measure the holes to be sure of their sizing as they could have been modified from as originally, but generally these will measure something around .440" which means a .500" press-in cup-plug would be to big; probably closer to a 29/64" as this would equate to .453" allowing for some interference pressing for retention.

    Better yet though would be to drill and tap these orifices for 1/4"npt threaded pipe plug application.

    B.T.W. the two each stakings at each hole indicate that these have been replaced previously and damage often as the result of this are an additional good reason to convert to a screw-in type plug. 

    Scott.