spray some starting fluid into intake-see if it fires off-if it does its definitely fuel system related---
On a vehicle that old you could have serious blockage in the filter sock, any lines could be deterioated, debrios in regulator etc
Also I think u may have to set timing by disconnecting some wire connector and set to 10 degrees then reconnect and ecm then sets timing electronicly
When u turn on the ignition can u hear the fuel pump momentarily come on????