Today Sun shined and so did the y block. Still a little fine tuning but thanks for all you help I could not have got to this point.

Well you all came through again! Everything is falling into place and she start runs good in garage. Could not have done it without y blocker help! Most of my issues were caused by me but you all got me through it.
Now have Mother Nature causing problems RAIN and RAIN. The weather here has been crazy have had few day that getting car out test driving. But hopefully this will pass and I can do test drive. But feel I should be very close to thr right tune. Thanks again to all!

I believe timing is at 8 - 10 kind of hard to tell as marks are hard to read.  Right now am going off the carb port for dist. vacuum. And as idle speed increases timing mark increases . Accelerator pump system check out ok. Vacuum gage show needs timing. Placed the plastic accelerator cam in #2 spot , will check timing again and take for test drive, later today.
The spring in vacuum diaphragm is the stock silver has anyone had to change it up or down?
What would be suggested to the timing? I believe my info show 2 for manual and 6 for automatic.

What are U setting the initial Timing at? Is the Vacuum Advance ported or non ported( full time Vacuum)? Using the Timing Light Is the Timing advancing steadily as RPM increases?

  

You can do most of the accelerator pump tuning in your driveway.  Just push the throttle wide open and take note of how the engine behaves.  If it stumbles, you need a larger squirter.  If there is black smoke out the tail pipe, you need a smaller squirter.  If it picks up rpm cleanly, with no stumble or smoke then it is pretty close and you're ready for a test drive to verify under load.



Lawrenceville, GA

Great information. Don’t know much about internals of the 312 I have but believe it is pretty much stock. I will look at what you suggested. And see what I finds. If the change to the #2 placement on plastic cam recheck the pump adjustment. If no improvement should I look at nozzle change ( go up or down ) or should I look at spring change on vacuum pump? Thanks

Ordinarily, you would swap nozzles, first.  However, on my 570, the #1 hole in the stock, orange cam did not touch the accelerator pump lever so there was some delay from the idle position before the pump activated.  Moving it to the #2 hole took care of that.

Before changing the position, take a look at down the carburetor and make sure fuel squirts from the nozzle the instant you move the throttle.  If it does not, take a look at the accelerator pump adjustment and make sure the cam is contacting the lever in the idle position.

Sluggishness can also be related to the mains but probably only if that is off by an extreme amount.  Depending on your engine combo, it could be.  The 570 is intended for near stock applications.  A bigger cam can throw it off quite a bit.


Lawrenceville, GA

First off THANK YOU ALL for you support and info. It did me good to walk away and see grand daughter and reset my brain. Thanks again as it helped.
Got the paper clip trick to work, secondary’s are working. Check timing and adjusted ( marks are hard to read ). But have a mark I use fo reference from. Seem to have improved but have kind of slow or sluggish pull to power. Going to try the reddish #2 hole in pump cam first, then maybe get the spring kit for vacuum secondary. It has a #31 nozzle but will try the other stuff first before looking at that.
Hopefully will not become stupid again while working through this. Great Forum with great people.

I have a 390 CFM on my 312, I can feel the secondary's open but they open slowly and you really need to focus on it, only problem with vac secondary's and manual transmission is the secondary's are pulled closed mechanically every time you lift your foot off the accelerator to shift (unless you power shift, not recommended with column shift).

They then have to start the opening cycle again. Not a problem for me as I drive like a grandpa, oh wait, I am LOL

Holley's are great carburetors.  I've had them on every classic car I have ever owned.  If you keep them maintained and use premium gaskets, they don't leak and they perform.  Don't give up and spend a lot of money on something that won't work nearly as well.  They're worth fixing right.