Drill and tap by-pass hose boss.

swat · Post by **swat** » Fri Dec 10, 2010 10:21 pm

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?

Post by **wesk** » Sun Dec 12, 2010 8:15 am

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.