Carb issue?

If i barely hold the secondaries open i can get it in the idle circuit and vacuum becomes steady and jumps to 12" . I may try the method again but think i will need a holley or larger CFM carburetor. The larger butterflies supposedly allow more air around them and may allow me to get to the idle circuit with Timing around 20 degrees.

Click to expand...

that is not correct thinking, even tho I think the 650 is a bit small.
Idle bypass air is correct thinking; , we all had to figure this out. It begins with about 270* advertised intake duration, depending on a few factors. Your Eddy cam specs are
308/318/112+5 @.006 "lift", and 234/[email protected]
This cam has exceptionally long and slow ramps, I mean the intake is (308 less 234)/2 =37* opening and 37* closing if symmetrical, and more typically a FTH cam would be 46*/2=23*; so 37 is 60* more than typical.
So at idle it acts like a much bigger cam than it is.
And the reason for that, is, in at +5 (107*) the Ica is 81*. At 81*, the piston is almost halfway up on the compression stroke when the valve is advertised to be closed, but is still only at .006 lift. It will be many more degrees before it is actually on the seat and not leaking.
This means at idle, the piston has ample time to push a lot of mixture back up into the intake manifold. And because of your altitude, that air has a lot less oxygen in it than it does at sealevel, so that makes it even worse. This is the principal cause of your low vacuum. The second cause is the lack of EFFECTIVE Compression Ratio; and the third is the lack of timing.
No matter what, I believe, you are gonna have to give it some bypass air.

If you are scared to drill the plates, you can introduce filtered air into the PCV circuit, but I recommend not to pull it out of the crankcase. BTW, do not run the PCV off just one runner; that cylinder will very likely foul the plug. The PCV circuit should enter the base of the carb just below the primary throttle valves. This is a perfect place to bring in bypass-air.