It probably has nothing to do with the new trans. I believe '96 will still allow you to check for codes, see if you have any. Other than that, check the relays and the circuits to the relays, sounds like something going on in the "auto shutdown" dept.

 

Spark, no start sounds like no fuel, check fuel pump relay.

 

how did you remove the tranny

when you replaced the tranny, did you pull the motor AND the tranny or the tranny alone? if you pulled the motor, there may be some lines mixed up, or something may have gotten into the line when the motor was out clogging it and not allowing any gas into the cylinder

 

do you hear the fuel pump cycle when you turn the key on?