denny w how do you set the tension or adjust the opening of the secondarys on a holley 850 dual line double pumper? , 76 1500 I've quadtriple checked myself on the wiring of the plug wires. what I'm wondering is it possible that I may have the timing chain off one tooth I really don't think that this has happened but who knows.What I did to this motor is replaced the oval heads with a set of newer style square ports installed a 268 dur./542int./554ex 110 lobe seperation lunati voodoo cam,a gm factory dual plane highrise marine intake, a holley 850 double pumper installed 81 primary jets,and 84 secondary jets last night,carb had 76 primaries and 80 secondaries still same problem,foloats set correctly, air correct, can't find any vac. leaks changed coils on hei same problem changed plugs, same deal, I set the valves[hyd.] on the engine stand according to the chiltons manual proceeder, should't be to tight.