I am a newbie so please excuse the probably obvious questions. Someone gave me a holley 3310-3 and told me it may or may not need a rebuild, when i slapped it on the truck (4.3L 1986 Chevy) wouldnt crank, i am on planning a 350 swap and this carb would be ideal...now my question is would the carb be able to supply with stock fuel pump? My guess is maybe not, and if so i will get the carb rebuilt

 

Those carbs only need 6-7 lbs to work.
On a 4.3????? What fuel pump are you using

I would absolutely throw a refresh kit on any carb thats been sitting. The gaskets shrink after being dry awhile and can leak once you start using them.
Kits are cheap check Summit