I'm going to be running Morel hydraulic rollers in my 273. That may be what yours are that have been reboxed. I didn't have the same problem as the OP has, but my lifter bores were too worn and had to be bushed. They were done on a CNC machine, and all the bushings were drilled with an .060 oil hole to lube the lifters. I've seen a 360 run on the dyno with the same lifters and same bushing setup, and they were quiet. I'm just wondering why others would tick?