Join Date: Mar 2002
Location: Austin, TX, USA
Those holleys were reved a few times and there are some differences between units.
As for the needle and seat arrangment...use the one that looks like what you took out. If you supsect it is wrong, you'll find out during the foat adjustment.
I belive you're correct in that some accellerator pumps used a needle that installed under the accellerator nozzle. Is there a captive ball on the bowl assembly where the pump diaphram mounts?
Float should be set level. Hold the bowl upside down and adjust the float level until its level. This gets you close. The final adjustment will come when the unit is installed and wet. You'll adjust the level until fuel just runs out of the inspection holes on the side of the bowls.
The air vent valve...I'm not sure about that one, since my carb doesn't have it. I don't think it's a critical adjustment though so if it hasn't been bent, it will probably install and operate as designed.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI