The carb in post #55 is an original Competition Series AFB, model # 4759, 625 cfm.
For reasons known only to Carter, they introduced another lot of 'Competition series' AFBs in the emissions era which were not the same & had different jetting.
#4758 to 4762 were five comp series, from 500 to 750 cfm.
The 4759 came with 095 pri jets 086, #606 rods [ 061/071 & had no choke.
What is odd & might explain the power difference is the sec jets. The only difference between the 625 & 750 is the smaller primaries of the 625. Secs are the same & same boosters, but the 750 has 092 or 095 sec jets, depending on whether it has a choke.
