1st Gen Transmisson Leaking

Looking for some advice here.

I have been battling a transmission leak on my 66 sportvan for a while now. I took the trans out and replaced both front and rear main seals thinking that was the problem. I drive it around the yard and what not, I park it and after a day or so there is a good size puddle under the trans.

I can't even see where it is coming from to be honest. Is there any place to look for on these Powerglides?

Anyone else have issues with the 2 speed trans leaking?

I'd suggest checking the dip stick tube. Pan gasket also. Fluid level rises at shut off.

I got PG in the 65 (Rat ina Box)with the 454 & the 68 G-20 (Ghost)with the 307 & they both leak if they set for very long. Replaced gasket , filters,& fluid on both pans (few times??)and still leak
Mine seem to be wet on pan(Have also checked them)

shifter shaft seal, speedo drive gear are possible leak
areas, dry it all with brake cleaner and let it sit for
a couple of days and see what gets wet. a shift seal leaking
will also look like a pan gasket leak. hope this helps

After 50 years of service, the pan can become deformed, especially around the bolt holes.