I am changing the rear main seal on my 312. When I removed the oil pan I found that the pick up screen has been removed. I know I should get one, I guess I am just looking for a second opinion. Would anyone else put it back together without it? 

Make sure the screen is in place.  It prevents larger debris from being pulled into the oil pump.  It's the first line of defense.



Lawrenceville, GA

Update:
I had ordered and received the oil pick-up tube screen. I installed the screen and installed the oil pan. I replaced the rear main seal with the engine in the car. It went in easier than I had expected. I followed Ted's instructions the best I could. Today, while the car was up in the air, I also replaced the gas tank with a new one from Tanks Inc., out of Iowa. I now have the oil pan installed but the sealant I used with the pan gasket says to let it cure 24 hours before use. As difficult as it is, I did not fill it with oil and start it. I will wait until tomorrow. I need everyone to cross their fingers that the new seal leaks less the the one I removed! I did use the black rubber seal. 

You don’t mention many specifics on the rear seal that you replaced so let me add this.  Just be aware that the 292 and 312 engines do require different rear seals.  While the 272/292 neoprene seal is available from the local parts store as the Fel-Pro brand, the 312 rear seal is not available from Fel-Pro.  As far as I know, only Best Gasket and Ford Craft offers the 312 specific neoprene rear seal.

Lorena, Texas (South of Waco)

SUCCESS! I think,,,,,,
Today I got home early, filled the car with oil, started it and let it run for 20 minutes with a nice big piece of clean cardboard under the car. After 20 minutes of running I shut the car off. There were NO drips on the cardboard! Then the car sat for 1 hour and still no oil drips. I looked close at the oil tube connections at the pan and the pump, no leaks there. No leaks around the oil pan either. I had removed the inspection covers on the bell housing before starting the car so I could see oil leaks quicker, but no oil dripped out. Before changing this seal it was about ten minutes of running and it would begin dripping.
The seal I used was a Best Gasket black neoprene seal with the side seals and nails.
I ran the car for about 10-15 more minutes to move it into its winter storage spot, put clean cardboard under it, and after another hour of sitting, there were still no oil drips!
I hope it is not premature, but I think the seal replacement was a success. 
My question is:  If it were going to leak, wouldn't be leaking after running for 20 minutes and sitting for an hour?

Congrats on your success!
I have my 292 out and had to have a bung welded onto my oil pan.  The previous owner had stripped out the drain plug.     I'm also cleaning out the pickup and tube and am now looking at the underside of the engine thinking "Do I go ahead and replace that rear main while I'm at it?"   It's tempting...but I've not done one on an engine this old.  My logic/lazy brain is like "if it ain't broke, don't mess with it!"   What do you guys think?  Should I just pull the crank and replace the rear main?

1964 Ford F100 w/ 292 Y-block
-Central Florida-

Sounds like one of those "might as wells". Since you have the engine out and the pan off now would be a good time. Plus you can inspect the crank and bearings. JMO