No preload on the gear, just a torque value. It's been a while, but, I believe the gear and fuel pump eccentric use a woodruff key, as does the cam gear.
I would get a matched set of gears, espically if you can see wear.
One other note, it has to do with the new cam gear. You will see, after removing the cam gear where to oil comes from for lubeing the chain and other parts. Pay particular attention on the new gear to ensure there isn't any cast flashing where the oil passes thru the center bore.
1957 WILLYS pickup,
1973 J 4000,
1978 CJ7 DD.
1979 CJ7 360, TH400/Quadratrac.
1980 CJ5 trail Jeep.
1989 YJ the CJ to YJ.