Drove my 73 340 duster with eddy heads and stock non adjustable rockers for several years with no problem...also used crane ductile iron rockers too...

Hughes sells quality roller rockers...

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)