what is largest cam for 340 with factory 10.5 flattops????????

mopar performance cams. 509 hydralic set lifters at zero lash. If you put in preload they will hit. 557 solid flat tappit. These cams were installed with standard deck height no head cutting but a pass to clean them. More duration makes more power on the average street car then more lift. You'll still have a real choppy idle and you won't have to get a high stall converter because the motor creates more torque on the bottom.. If its a 4spd. car Go for the lift and scream the sucka, I did and still do. I start my chainsaw up now and then over the winter just to hear it. I was thinking of putting race fuel in it for the smell. Steve