It was obvious our stroker 540 was running out of breathing room with the smaller camshaft from the 502 testing. To take full advantage of the Dart Pro 1 superior flow, we swapped in a higher lift cam with more duration. Our new Extreme Energy camshaft (XR294HR) came as a complete kit with timing set and even included new retrofit hydraulic roller lifters. The lifters not only decrease friction over flat-tappet designs, but these will accept much more aggressive cam profiles. Our camshaft spec’d out with a duration of 242/248 intake/exhaust at 0.050 inch with 0.540/0.560-inch intake/exhaust lift and was good to 6,200 rpm.