[quote]The Holley 1920 pulls 11" of vaccum. The 1945 wouldn't even idle long enough to check vaccum and it was so speratic I couldn't get a good reading. [/quote]
One point, carburetors don’t pull vacuum, movement of pistons, cam event timing, and mechanical condition of engine & valve train dictate vacuum strength. Carburetors mix air & fuel based on how much vacuum signal they see at any given moment.
You tried two different carburetors, one wouldn’t let engine idle, the other worked a bit better, right?
I suppose that both your carburetors could be malfunctioning, but have you tried them on a well running engine to see if indeed they are in need of a rebuild?
Cranking down on carburetor nuts “all the way†is not a good method. Improper torque applied to nuts, and bolts in general is counter productive, and stretched fasteners. Also often can cause damage to a carburetor by warping its base. Once base is no longer flat, vacuum leaks are common, throttle plates may not fit properly causing idle problems, and cracked parts.
You should find a torque wrench, and torque all fasteners to factory recommended specification each time a repair is made. Following this procedure will result in a better and safer repair.
I still think you have a vacuum leak, most likely between carburetor base and intake manifold, carburetor throttle shaft, intake manifold and head, or in power brake system if you have them. Don’t discount a crack in manifold seam if it is aluminum.
Remove carburetor, place a straight edge in north-south, east-west, NE-SW, and NW-SE directions, look for distortion, or rather, cupping of its base. Using a light will help to see any distortion. If you discover any distortion, the base needs to be filed flat by using a #12 mill bastard file. This will take a bit of time, you will need to have a wire brush on hand to clean file as you go of aluminum build up.
Once carburetor is able to seat to manifold with out gaps, install with new gasket being careful not to over tighten the nuts.
To test for leaks around head to manifold, spray carburetor cleaner around each intake runner listening for change in idle speed, which is an indication that you have a leak at that spot.
To test brake vacuum, remove vacuum line of power brake booster at manifold, and seal off manifold nipple listening for idle quality change. If no change, booster & plumbing are ok.
On the electrical side of this problem; are your plug wires doing their job? Did you damage them when removing from plugs?
You are using a HEI that produces 10 to 15,000 additional volts over a stock ignition. Your plug wires may be leaking voltage to ground before it is delivered to respective spark plug. Observe the wires at night, if blue streaks are running along them, you need new wires capable of handling higher voltages. Or if each time you touch a plug wire you get bit, change them.
Give this [url=http://www.magnecor.com/magnecor1/main.htm]site[/url] a good read to help understand what can go wrong with plug wires.
Bill
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Gave it a little gas and at higher rpm it did better. Already knew about the small vac leak as said in earlier post. Figured it had gotten bigger. My house is 17miles away, I decided I could make it. I made it home, but my exhaust sounded like a machine gun fight from a scene in Rambo and my truck was bouncing around the road like a rabbit jacked up on mt dew. I know the carb is tight, it's as tight as it's gonna get unless I use an impact gun. I'm going to check the intake nuts and make sure they are tight.
So there is more money I'm gonna have to pull out of thin air.