Oil Pan Sealing Tips LA Small Block?

[Too Many Projects]

Bill, was the 1 piece plastered with silicone at the ends ? Silicone will cause the blue seal surface to NOT seal and leak. I've installed several of the 1 piece ACCORDING TO THE DIRECTIONS and have had no leaks.

I haven't used the 4 piece either cork or rubber for many years. As has been mentioned, change the rear seal and install the ends offset from the cap seam by, at least, 22 degrees with a minute touch of gasket sealer on the ends, not silicone.
And, as has been also said, for any of the various gasket types being installed, ALL surfaces need to be sterile, If a white cloth doesn't come back without any discoloration, I keep cleaning and the final clean is with acetone.