1992 Pontiac Bonneville

My car has recently had issues with stalling. This is an intermittent but persistant issue when it happens. There was a prior incident of the same type approx. 6 months ago, which ceased after running "seafoam" through the crank case and gasoline tank. This led me to believe it was a fuel injector issue.

Recently my car has stalled 3 times in a week. Twice I was able to restart the car immediately, the third time it took approx. 25 seconds of cranking. Currently halfway through a tank of gas w/ "seafoam" additive.

Plugs are clean, wires are intact and my mech claimed the engine wasn't in need of a tune up.
Have noticed that oil pressure (once the car is hot) will run slightly below 40psi at idle.

It has also began to "buck" after a stall and restart (usually one time, sounds like the transmission slamming from 1st to 2nd gear). Recently had a trans leak from rotted hoses, they were replaced quickly.

So fellows, what is ailing my near ancient PB?
Many thanks for any info.