Need Advice Please on a Persistent Oil Pan Leak

[paulsec]

Need help please on a 69 Camaro SS with new rebuilt 350 engine that has oil leaks at the front and rear oil pan seals. Leaks at the bottom of the pan seals when the engine runs and after shutting off.

Round 1: New aftermarket Taiwan stock oil pan and stock gasket/seals (thick front seal) = leaks

Round 2: New aftermarket Taiwan stock oil pan and Fel-Pro one-piece oil pan gasket (thick front seal and longer ARP pan bolts) dry with Permatex Ultra Black sealant in the four seal corners = leaks

Round 3: New aftermarket Moroso stock oil pan (thicker steel, USA made) and Fel-Pro one-piece oil pan gasket (thick front seal and longer ARP pan bolts) dry with Permatex Ultra Black sealant on the inside and outside of the front and rear oil pan seals = leaks
 
PCV valve is good. Pan is flat. Pan holes are flat. All surfaces are clean. I'm out of ideas. What do you recommend next? Thanks for any input.

[GMAD_Van Nuys]

Previous discussion on CRG concerning oil leaks:

https://www.camaros.org/forum/index.php?topic=7819.0

[bcmiller]

When you replaced the gasket did you have the engine on a stand upside down?  Replacing with the engine in the car is difficult to get a good seal in my opinion.

If you did that, I would try a good used original oil pan.

[rich69rs]

Any possibility of overfilling with too much oil in the replacement oil pans?

Richard