Check ,with the cap removed , does the rotor go around when cranking the engine over. The pin in the distributor gear can shear, mine just did it again. I have it down to less than an hour. Removing distributor.finding the extra pins , replacing the sheared pin in the distributor gear and shaft , gathering up my tools ,turning crank shaft over to TDC ,and firing up the air compressor ,removing #1 spark plug.blowing in #1 hole to see if both valves are closed, setting distributor ,conecting timing light, and so on. Oh you won't have any
oil pressure either.