End play in the Camshaft will make a rapping noise, check to see if the bolt is too long, it is supposed to be a 7/16"-NC X 1- 1/8" with an external tooth washer. Sometimes a longer bolt is used to install the Fibre Gear and the original is not replaced. You can remove the fuel pumb and try to check the endplay by prying the cam back and forth. Did you use the proper spacer for your fuel pump?
PROUD 2011 MVPA PIONEER AWARDEE-HONOR GRAD WHEELED VEHICLE MECHANIC SCHOOL 1960- US ARMY ORDNANCE SCHOOL(MACHINIST) APG 1962 - O-1 BIRD DOG CREWCHIEF - 68 NONSTOP BY THE BOOK ARMY TRUCK-JEEP YEARS LIFETIME AM LEGION DAV 40/8- MVPA 1064 -7 TURNKEY MV'S