I warm engine, put it on TDC and hook up tester. Adjust inlet pressure to 100 PSI. Look at cylinder gauge. Subtract whatever it reads from the 100 PSI. That is your leak down percentage. Continue through firing order to do rest of cylinders.

67 Barracuda street/bracket car 11.27-119
68 Dart 502 BB 8.70s-152
414 cid SB Dragster 7.65-174