Torque converter drainback
 

If I let my 68 GTO sit more than a couple of weeks, I'm greeted with a sizable puddle of ATF under it. I'm told this is ATF draining back into the converter. Any solution to this, other than driving it more?

It shouldn't be leaking anything. My 69 G/P does the same thing. I've swapped out the torque converter and the converter to front pump seal twice. Still leaks. I figure it's either the front pump to trans case gasket/seal or the pump or case have a sand hole (porosity).

Could be wear at the front pump bushing, not a expert but did stay at a Holiday Inn once.

I am no expert at this either, however had the same problem with my 68 a few years back. Huge puddle underneath after sitting for the winter. My buddy told me it's leaking around the dipstick seal. I replaced mine and sure enough, that took care of the problem. Hope this helps.