1978 Chevy Impala

Do below to determine if its fuel or spark and get back

Get a carb cleaner and spray into the carb or the throttle body on an EFI. Did it start and die? If not disconnect a sparkplug wire or 2 and ground it to the engine -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, distributor pick-up coil, ignition control module, cam and crank sensors- Note: If it doesn't apply disregard it

Timing chain

This is my concern-when you replaced it did you double checked if the engine no. 1 piston on its compression stroke-if its on the exhaust stroke it w/n start, the valve timing is off.