Here's the only information from the Holley Illustrated Parts & Specs Manual:
R-8051AAA (1-344 & 2-258)
Model 2280 & 6280
Typical View Illustration No. 46-1
1964-65 Chevrolet 283 Eng. ALL Trans.
Dry Float Setting - measured with main body assembly inverted, from the toe of float to the face of float stop.
Pump Link (or Cam) Position - No. 2
Choke Unload Setting (WOT) - .290"-.330"
Choke Qualifying Dimension (Vacuum Kick) - .145"
Fuel Pressure - 6 P.S.I.
Renew Kit 3-875
Variable part numbers not on Holley's illustration:
(2 choke shaft) 3R-657A, (3 dechoke lever) 4R-1191, (6 throttle stop screw) 5R-1175, (7 fast idle screw) 5R1055,
(11 throttle plate screw) 5R-1537, (20 throttle body & shaft) 12R-7849A, (21 throttle return spring bushing) 13R-1263,
(22 idle adjusting needle) 15R-149, (26 nozzle bar assy) 21R-748A-7, (27 main jet) 22R-130-279, (30 power valve assy) 25R-721A,
(37 choke diaphragm link) 33R-586, (42 complete choke diaphragm assy) 9-211, (46 throttle stop screw spring) 38R-1559,
(47 fast idle adjusting screw spring) 38R-1715, (51 throttle return spring) 38R-1908, (57 fast idle cam) 41R-774, (63 pump link retainer) 48R-183-3
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, cold air induction, dual 3" exhaust/Magnaflow mufflers, 100HP progressive dry direct-port NOS, A/C, Lentech Strip Terminator wide-ratio AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, custom traction bars, 4" lift, 35" mud tires