I also have a job coming up & will be using the Deep style brass core plugs...Seem to fit better than oem shallow type...

 

1 5/8” in the side of the block. I like deep, more surface area to seal.

I recently use shallow ones, a few has some seepage weeping until it was driven Some and a had a few heat cycles.

 

Actually our stuff is 1 41/64ths" which is just a smidge bigger than 1 5/8". Also they are shallow and the Chebby 1 5/8 are deep.

 

Milodon makes a nice packaged kit, USA made. Don't forget the threaded plug that goes in the bottom side of the oil passage behind the timing cover!

 

Thanks for the lesson. Kim

 

Mine were pretty porous during the rebuild on my 440. I had to machine them all and bore the to 1-3/4" cup plugs.

 

Holy that must have been pretty rusty. Kim

 

Yes, surprisingly everything else was fine. Over 55,000 miles on it now since the rebuild.