The heads are 452's from Aero Head that have 2.14/1.81 valves. The heads were surfaced so probably close to stock cc. The short block is close to zero deck after going with L2355 flat tops.

Please define drone for me because I don't really know the term.

Project War Bird: 1971 Plymouth Roadrunner 383 4 speed with air conditioning GY3 Curious yellow All original