engine miss

[oktire]

So I'm putting a car together for my wife 408sb the motor has a nasty miss from 3700 to4700 when in gear it dose do it in park but very little when driving it's in all gears once you get above 4700 it takes os again. put new plugs/cap/rotor/wires it has msd 6al and a new 750 vac holley. thank for any help..

 

[1wild&crazyguy]

So I'm putting a car together for my wife 408sb the motor has a nasty miss from 3700 to4700 when in gear it dose do it in park but very little when driving it's in all gears once you get above 4700 it takes os again. put new plugs/cap/rotor/wires it has msd 6al and a new 750 vac holley. thank for any help..

Try a Lighter spring in the secondaries
I would also check the plugs for primary/cruise jet color and if need be , jet up on the primary