stalling

[1983shorty]

i just got my 350 implant together and was going to test drive it today. seems to idle ok and rev in park ok but when i put it in gear it wont stay running. bogs and stalls out. also getting a " knocking sound" from the distributor. put my stethescope on it and definitly from inside the dist. got a brand new holly carb on top. maybe the floats not right ? didnt check it out too much today didnt have the time. any ideas on the stalling ? ill have to pull cap off the dist. to check it out. sure does sound mean with the headers and el- cheapo dual exhaust !