Interesting video on lifters

Some FT cam lobes DO require lifters with no chamfer because the aggressiveness of the rate of lift requires the full lifter diameter. Take the simple 0.842" lifter & put a 0.020" chamfer on it. It's effective diameter becomes 0.804".
Crower makes specific no-chamfer lifters. Example: Crower 220 series Chev sol lifter series cams require no-chamfer lifters. The same principle applies to Ford & Chrys lifters/lobes.