Hey 058

[Blown 472]

I am putting my 472 back together and I have checked and rechecked every clearance and so far so good, the question I have for you is the that tappered plug in the front of the motor, I put it in and looked down from the feed hole from the main brg saddle and there were about four threads and the tapper part showing, so what I did was grind the threads back to a tapper so all the oil sees is tapper and not threads, what do you think?

[058]

Blown472, You are on the right track. The biggest mistake most people make is to install a straight cut plug in that main gallery hole cutting off most of the oil to the #2-3-4-5 mains. Also I have found that oil passage is in deeper in some blocks than others so you could "get away with" a std. plug and still get oil to the engine but I found a few blocks with the passage so close to the surface I was afraid to use even the tapered plug.

[Blown 472]

Ok, if the tap is deeper and I went with a flat plug what would the pro or cons be, does that tappered plug direct the oil or what is the purpose of the tapper??

[058]

The tapered plug does not go in as deep but has to be short enough to clear the timing sproket. A straight cut plug has a longer thread reach so if you screw in a straight plug it can shut off some or most of the oil to the gallery running the length of the block. Some tapered plugs seem to be slightly bigger so you can't screw them in too far. They do not direct oil anywhere, just block off the gallery.