Most of my past vapor locking issues have led me to the fuel pump push rod. The rod over time wears on one or both ends, shortens up, and doesn’t allow a full pump lever stroke. Assuming you still have the mechanical pump installed.

1968 Barracuda Fastback 318-2BBL 904 2.76 Frost Blue Survivor
1970 Roadrunner 440+6 BBL 727 AT 4.10 SG Dana Blue Fire Metallic
1971 Cuda 340-4 BBL 4spd 3.91 SG Curious Yellow
1972 Barracuda 318-2 BBL 904 AT 3.23 1 Legger Tor Red/White Vinyl Top
2007 Dodge Ram 1500 5.7 Hemi AT Patriot Blue
2011 Dodge Challenger RT 5.7 Hemi 6spd 392 SG Triple Black
2014 Dodge Charger RT Max AWD 5.7 Hemi AT 305 Billet Silver