I have a 95 Monte with about 245,000 miles. It has always ran great until one day I stopped at a light and it stalled and wouldn't restart. Engine cranks the fuel pressure was about 15psi so I replaced the pump and filter. When I try to start it now it backfires and makes a knocking noise. Timing is good. I checked all the basics and I'm kinda stumped here. It didn't overheat it was running fine and then just stalled. HELP

Welcome to AF, no way to diagnose this over the I'net, sounds like a catastrophic internal failure, pull a valve cover off, see if all the rockers are moving.