"Billy, you are 100% correct.
"Billy, you are 100% correct. The intake manifold kit included the O-ring and gasket for the distributor. I was quite a bit slower than Jeff L & Son. It took me over 6 hours on my own to drain the block and replace the intake manifold gaskets. I ran her about 3 hours today with no signs of leaks. That's the good news. The bad news is: The photo below shows why the leak developed, and I expect it will return. The gasket design is terrible. The metal insert is too large for the sealing surface , especially near the top left corner of the photo below, leaving less than 1/16 of an inch of sealed gasket surface where the exhaust passage from the cylinder head enters the intake manifold. The gasket only fits one way, and there is no way to reposition the flow restrictor to improve the seal. The section of the gasket directly above the restrictor is unsupported by the cylinder head and was so baked out from the hot exhaust gas passing nearby that it cracked out on both the port and starboard sides of the engine as soon as I touched it.
As to Jeff L.'s question, where does the oil that leaked on top of the manifold come from? That's note quite a complete story for me. In my case, the oil (oily water really) came from space around the exhaust port (which looks in the photo like an inverted letter U). This space seems to be a dead end which doesn't appear to be connected to either coolant or oil passages directly. I think it was included in the cylinder head casting to maintain a constant wall thickness around that area of the casting. (You can't leave a thick section of metal when fabricating a complex casting or it will distort or cause sink marks to form.) In fact there is a small gap where water can enter that inverted U space in the cylinder head just below the valve cover on either side of the carb. I think that if things are working properly, any small amount of moisture that gets in this opening will simply evaporate from the heat of the engine. The only way that I think oil could enter this space is from blow by in the exhaust when exhaust is leaking from the restrictor. I had a milky brown mix of water and oil in the space around the exhaust passage, which I cleaned up with paper towels before replacing the manifold. it wasn't a lot of oil, I absorbed it with a couple of paper towels when I first noticed it. I didn't have time to do a compression check this week, and she seems to be running well enough. Earlier in the spring, while cleaning the top of my engine I sprayed a hose momentarily around that area, which I'm pretty sure is how I got water in there. when I heated the engine up under load and exhaust mixed with the water in the U shaped gap, it bubbled out from where the top of this inverted U isn't sealed onto the top of the intake manifold looking foamy like contaminated oil. Any other theories out there?
I'm kind of pissed about the gasket design. It looks to me like the only reason for the bump at the top left corner of the restrictor which compromises the seal on this surface is so the two halves of the restrictor can be made from one stamping. the two parts of the stamping are joined together at the bump which you can see at the top left of the photo. This badly compromises the seal, leaving only the tiniest sliver of sealed gasket. If the bump to join the two parts of the stamping had been at the bottom of the exhaust port, where there is a lot more meat to the casting the seal would not be compromised like this.
click for a higher res image
http://farm4.static.flickr.com/3326/3605217911_c20d64548f_b.jpg"
and an overall view of the block & heads with the manifold removed.
http://farm3.static.flickr.com/2482/3606036746_f06ce9b34c_b.jpg"
Thanks again for you input and advice.
PS, when i went to install petcocks on the block drains, the Starboard side was fine, but I was unable to install the petcock on the port side because the butterfly handle of the petcock hits a nearby boss that is part of the engine mount. you can install the petcock, but you just can't close the valve. I simply put the pipe plug back on the port side of the engine.
Best"
