Page 1 of 1

Drill and tap by-pass hose boss.

Posted: Fri Dec 10, 2010 10:21 pm
by swat
My M38 engine, MC56226, has a 800376 cylinder head but the by-pass inlet hose boss is not drilled and tapped. How far down from the top of the boss should I center the drill, and should it be tapped for a 1/4 NPT?

Posted: Sun Dec 12, 2010 8:15 am
by wesk
It is not uncommon for the undrilled civvy 800376 head to show up on the M38 engines out here. I don't have my assembled block here right now but all you need to do is set the head on your block with a head gasket and install a new 90 degree bypass hose on the water pump and mark the target on the head.

Image

Image

Image