- Jan 3, 2014
Thank you.Bob Hoover has a measurement for drilling the passage in the case as 8.872" or 8 7/8" long. I mark my long drill bit with several wraps of tape and I stop about an 1/8" short. Then drill the passage down from the cam bearing saddle and both holes should just touch. Then finish both drilling . Have drilled 3 cases with no problems. To me grinding the grove in the rocker arms is the hardest part of the mods. But now it look like you can buy new rocker arms already grooved from CB Performance .