stockish 340 maybe a 6 pack good or bad ideal??

so i have a 340 in the car now i can tell its been gone thru but dont know any thing about it.
i would say no more then 10 to mild cam stock x heads
hp manifolds elc ing

im wondering if i throw a 6 pack on here what it will do kill the car or make it fly. not sure even if i down jet it if the flow is right some motors just dont run with some set ups

so whats your input