I have no experience with the early 6 cylinder engines, but the front and rear surfaces of the oil pan in the 4 cylinder engines are difficult to seal.

One of the things I encountered when rebuilding a 1928 engine in 2017 was the issue of installing the oil seals so they would not leak. I documented that journey on the old website (vccachat.org) and here is a link to the post where I made and installed the gaskets for the oil pan: Making oil pan gaskets for a '28 4 banger

Hope this helps. Cheers, Dean

There are tricks. I copied this from the 46 section of the old forum by Chevy Gene ;

When replacing the oil pan gasket the side gaskets must be stuck up onto the block first and then the end corks inserted into the main bearing caps. Pre-curl the end corks before installing. Saves a lot of swearing. I uses 4 little studs , insert them into the block, to guide the pan straight up into place. This helps to prevent the gaskets from slipping.

You can pre curl by wrapping around a soda can with rubber bands overnight. I also use a little grease to hold the side gaskets on the block while putting it together. Also a little sealant where the side and end gaskets meet. 

Try searching the old forum lots of ideas on this subject.

Good luck

Dave

I put all gaskets on the pan.  I like your input and will drop the pan and start over.

Wetting the cork end gaskets before wrapping them around the soda or beer can and letting them dry overnight is critical to forming the arched shape.

@chip Great Tips Guys.  I too have serious front and rear oil pan leakage on my 29 six cylinder.  Just got the 29 a year back, Jan 2024, and I immediately changed the oil pan gaskets the first time, with the gaskets in place on the oil pan with a light coating of oil pan gasket sealant and then placing a small bead of oil pan gasket sealant on the top of the gaskets, then, with six guide pins I made, lifted the oil pan up into position and tightened the oil pan bolts.  Waited 24 hours later, installed the oil and took the truck out for a ride.  Still had oil leakage front and back like it originally existed.

Did the project over again, mostly using the same technique.  But this time after the oil pan was seated, bolted in place, I applied a glob of oil pan gasket sealant at the four points were-as the curved gaskets meet the flat oil pan gaskets.  I felt that was the points where the oil leakage was coming from.  Nope, I still have the same front and rear oil pan leakage.  It's like I never did the job.

So,  I will follow the previous posting listing on this issue, which is different than my expectation, which mine did nothing for me other than driving me crazy.

I luv this place (VCCA)

Thx, G