1990 lumina automatic trans. pan

i have a 1990 chevy lumina . i am having a problem keeping the transmission pan gasket sealed. i can't get it to stop leaking. what are the torque specs. for the transmission pan and how do i go about tightening the bolts. Do i stager the pattern or just go around the pan.
also this is a crazy question but, is there a cadillac strut out there that will fit a lumina?

Are you, or have you ever, used a cork or paper-based gasket aside from the factory-reusable one? If so, then torquing to the correct specs with the other gaskets can dimple the pan around the bolts, causing the space between the bolts to not seal correctly. Look into that first.

You might have a warped pan, be sure to check both the transaxle and the pan for warpage, gouges, or old gasket material.