they come with adjustable rockers but the stock cam was hydraulic...

if it is a solid cam then someone change it out...you will need to find out what cam is in it to find the lash for that cam.

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)