Plug in air horn directly over APT

[Dave57]

Working on my 1980 Vette #17080228 carb. I am modding per #2 recipe and in the process of reassembling with a Cliff's gasket kit. There is a aluminum plug in my air horn directly over the APT adjuster screw. Can this be removed permanently, or will I have to remove the air horn to make APT adjustments? Also, can I shorten the acell pump shaft 1/8" on 1980 kit? I read somewhere that they were already shorter than early ones. Dave

[429bbf]

not sure on shortening the shaft  but knock the plug out and tap to 3/8 don't go to deep and install a 3/8 allen plug . that way you can adjust the apt without taking the carb . tap it just far enough so the top is flush so the gasket seal the dirt with the air cleaner. 3/8 bolt thread not pipe course i think its 16threads per inch. fwiw

[Dave57]

Got the hole tapped for a set screw. Still wondering about shortening the accelerator pump shaft about an 1/8".

[Cliff Ruggles]

Why would you want to shorten the pump?......Cliff

[Dave57]

My motor is a 383 CI ~ 425HP. I enlarged accel discharge holes to .030" per recipe #2. Years ago I was lead to believe that shortening the acell pump shaft would increase the volume of the shot by raising the start point of the pump.

[Cliff Ruggles]

Do you have a hesitation/stumble/bog issue going very quickly to full throttle?

The accl pumps we put in our kits are shorter than stock, and if you indicate you want an HP pump we will put one in the kit at no additional cost........Cliff