Technical question about early SBF pan/rear main seals

I started my '64 Fairlane a few days ago in like 25' weather. I noticed a large puddle of oil under it's original 260 V8 after the engine got warm. I peeked under the car and could see the oil leaking out of the top of the rear of the pan.

the leak doesn't seem to come around until the engine gets to operating temp. is it more likely to be a pan gasket or a rear main seal? thanks! <!-- / message --><!-- BEGIN TEMPLATE: ad_showthread_firstpost_sig --><!-- END TEMPLATE: ad_showthread_firstpost_sig --><!-- sig -->

 

probably the rear main seal.

YOu can try tightening the pan bolts a little, that might help if it's the gasket.

 

Sometimes after years of snugging the pan rails will distort,probably best to drop the pan and replace the gasket and end seals and flatten out the bolt holes.Had a similar leak it was the pan seal.

 

X2 what Jeff said. The gasket & end seals that might be 40yrs old will be fossilized anyway.