I put a duble pumper on my 340 and love it. Jets are 72s primary and 84s secondary. I personaly dont care for the 3310s and have 2 ill sell. I dont like the fact that the secondary side dont have a meetering block, so no jets to swap around unless you buy the kit. Also hate swapping springs every time you put the carb on a diff engine. Secondary opens on vacume, witch is determined buy what cam you are running. Have ran the 3310s, but the double pumper seems more responsive.
