FYI
I know people have asked about this torque spec.
In the Pontiac Service Manual, the torque for the gasket is 12 ft-lbs or 144 inch-lbs.
I had the tranny fluid + filter serviced 2 years ago. It started leaking 2 months ago. The bolts had been over torqued as the gasket had been crushed especially at the front - slightly extended beyond the cover & curled & split.
The orig gasket from 1984-May 2022 never leaked.

 

That says it all. Even if you have one of those reusable crush resistant type of gaskets with an o-ring around it into it, all pans should be torqued.

 

Something I've observed with trans pans when doing a service and that's how even the pan rails are.
I've found more than once than the edges become wavy and the result is a loss of seal between the bolts. Over torque will do this. It'll also happen with a pan that's been removed and reinstalled many times.
I invested in a new pan and many of my previous leak issues went away.
Also of note is the type of gasket and whether any RTV type sealer has been used. Most shops use a cork gasket installed dry.
I'm a failure in that regard.
Best results for me are with the heavy "paper" type with a thin smear of RTV on both sides. I'll install the pan and only hand tighten the bolts so the RTV makes contact with both surfaces (transmission and pan). After the sealant has had some time to cure, about an hour, I'll proceed with a proper torque sequence.
Seems to work.

 

I use the rubber standard gasket. Tighten the bolts until I just see the gasket being squeezed at the bolts. Has always worked for me.

 

That was my definition as U stated. The fellow at this transmission shop has retired several years ago & he was the fellow who always worked on my '72 Buick GS. He used a 1/4" drive & tightened again as U say. Over the years I had him service 4 TH350 trans & never a gasket leak after the services.
I am printing the specs on the previous bill + to be sure that the rail with the bolt holes is flat .

 

Any sealant?