Overlap is what makes the idle sound cammy not so much duration. I can spec a cam that will lope like crazy at 550-600 rpm and make more torque than the stock cam by ~1,500 rpm. The old Crane 274H06 was one such cam. It was ground on a 106 LSA and 102 ICL it had a choppy idle and was a stump puller even in a low compression 305.
Those type of cams, short duration and tight LSA's, are still pretty popular in in smogger 318's and 360's for a big torque bump. Think Cranes version for the Mopar is 216-218 @.050, .454 lift. @106 installed + 4. Crower has dropped off the radar, but used to have what they called mileage master and torque master grinds. I always look at the IVC, EVO, overlap numbers , and generally run the stuff through a DCR calculator. They'll still perform the same way in the same combo as 50 years ago and easy on the valvetrain.
