the old roller lifters would uncover the oil galleries ..hence the need for the tubing..

new solid body lifter do not ...so tubing is not needed...but if you kick a lifter out of the bore you will lose oil pressure..but that is the same with flat tappet lifters as well as roller lifters..

Tony

70 AARCuda Vitamin C
71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield)
71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas)
71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)