I was wondering what jet sizes I should be using in my Holley 600 vacuum secondary carb? The engine is a 351 Cleveland with 2V heads, Comp 268H cam, Performer intake, headers, Crane ignition etc. The engine is in a '71 Torino. I am currently running size 66 jets in the primary side and 64 in the secondary side, but have been told these are much too small for my cam and may be causing a high rpm misfire I have got. I am going to fit a set of 74 and 76 and try them anyway but I would be interested to know what sizes you guys are using.