3892657 Engine Block Distributor Tower

[dans67camaro]

I have a 3892657 engine block I am rebuilding (numbers matching) for my 67 camaro, 350SS/RS. The distributor tower that is cast into the block in the oil galley is the tall style. There is a 'sleeve' pressed into the distributor hole, and there is an angled (down) hole drilled through the tower from the oil galley into the distributor hole and through the sleeve. However, the hole appears to have been welded closed! I have a 68 block w/o the sleeve and the hole is open. Does it matter if the hole is open or not? Confused!
Thanks... Dan

[hotrod68]

Dan, I don't understand what you mean by the "tower" or "tall style", but I can tell you that the '67 blocks had an extra hole in the back of the block for a breather tube. This tube was eliminated in '68 when the blocks were redesigned for the larger main crank journals and spin-on oil filter, and the breather tube was replaced by a PCV valve. Hopefully this will help you in some way. I've never heard of this and hope someone else has! Maybe it was an attempt to restrict oil to the rocker arms for racing?

[dans67camaro]

Thanks for the response. The distributor 'tower' is cast vertically at the rear of the oil valley. This is the valley where the holes are drilled for th lifters. The distributor is drilled out vertically with a hole for the distributor shaft. This is standard and in some blocks, the top of the tower is nearer the bottom of the valley (short tower), and some, like mine, the top is up near where the intake seals on the rear of the block (tall tower). I have seen several pictures showing this tower, some with the cross drilled hole I have a question on, and some without the hole. Still looking for knowledge.... Dan

[JohnZ]

"Tall towers" were very common on 327 blocks, and the 657 block in my '67 Corvette has one too. I've never seen a sleeve in a distributor hole, but there should be two oil holes in the distributor hole - the groove in the "spool" on the distributor housing connects them so the oil galleries for the lifters on both sides get oil pressure. Do you have a picture that shows the condition you described?

[dans67camaro]

 I do have the cross drilled holes (one in the front and one in the back) in the bottom of the distributor hole . The one I have the question on is drilled from the outside to the inside, about 1-1/2 inch down from the top, and about 1 inch above the the oil galley where the #8 lifters holes are. It is drilled slightly at an angle front to the back of the block and angles down from the outside to the inside at about 45 deg. I  don't have a picture, yet!

[dans67camaro]

Does anyone know what the hole size should be for the machined hole in the rear of the engine block that the distributor housing slides into??? I want to be sure I have the correct slip fit with the distributor housing. I believe its specification is 1.2485/1.247.

[JohnZ]

See the other thread.