Vacuum dashpot adjustment
 

Hi. Can anyone share the adjustment procedure for the vacuum operated dashpot on a 1965 Pontiac with a 326? Thank you

You didn't say if you have a 2BBL or 4BBL so here is both.
On 4BBL carbs make sure fast idle speed is set first then shut off engine. Rotate fast idle cam so that screw is on highest step of cam.
On 2BBL carbs rotate fast idle cam so that speed screw rests on the NEXT to the highest step.
Measure the distance between the dashpot contact and the throttle lever. The clearance should be:
4BBL .090 to .095 inch (HI step)
small 2 BBL .062 to .067 inch (2nd step)
large 4BBL .090 to .095 inch (2nd step)
If adjustment is necessary hold sleeve from turning and turn contact screw.
Hope this helps.

Thank you. I really appreciate it.

I missed typed!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1
The 3RD measurement should be LARGE 2 BBL carb NOT 4BBL

Thank you, can you tell me how I could distinguish the large 2 Barrel from the small 2 Barrel?

Goatracer1,
If it's not too much trouble, do you have a shop manual that shares that information on the dashpot adjustment you shared below that you can photograph the page and share it with me for my records? Thank you

Your routing of the fuel line is a good recipe for percolating and vapor bubbles in fuel line.

JMHO

Your ‘65 326 has the large base Rochester 2-barrel.

The only engines that used the small base 2-barrel in 1965 would have been the Tri-Power 389 or 421 which used the small base center carb.

I also could not find the source for Goatracer1's instructions. When I checked the '65, '66, & 67 Pontiac Chassis shop manuals, the instructions differed although I suspect you get to the same result. From the '65 Chassis Shop Manual for both 2BBL & 4 BBl:

THROTTLE RETURN CHECK ADJUSTMENT
(AUTOMATIC TRANS.)
1. Set hot idle and mixture adjustment to specifications.
2. Place transmission in neutral.
3. With engine running adjust diaphragm plunger
screw so that when hose is disconnected and plugged,
engine speed of 1030-1080 rpm is obtained.

Thank you for the info. Much appreciated.

Ive been thinking about that fuel line also.

John

I see that Ames reproduces the '65 4 barrel fuel line (N129A) in steel. It may require the inline fuel filter.

Many moons ago before it was reproduced, I made my own out of steel following the original's contours and extended it all the way to the fuel pump. The original was made of aluminum.