Hi , check choke idle and related screw and spring ,  also how works throttle linkage and dashpod . 
Try to force the throttle to close . if works maybe is only  to set correctly links and joint  . 
From my experience some air leaking from intake , raise the idle ...   it's happen to me and was easy to find after mechanic explain me how to do it .  with oil lubricant he follow the intake border and start the engine with low idle . the oil keep only a little time the air passage close  after that returns high . 
I feel you are very sure that your engine don't suck air from somwhere .  how did you check it ? 
After that i don't know anymore to help you .  bye !

Thanks guys.....

I have the secondary blades backed off entirely and front Main Idle screw is backed off all the way (no longer in use)....before assembling and bench testing I ensure blades shut entirely, then I set them.....obviously tweak on car!.....

Jets are 56P and 63Sec with a 6.5PV.......maybe primary Jetting is too High?  but that would confused me only cause those came off a 1.14 2bbl autolite.....this is strange!

M1Mustang69 wrote:

Thanks guys.....

I have the secondary blades backed off entirely and front Main Idle screw is backed off all the way (no longer in use)....before assembling and bench testing I ensure blades shut entirely, then I set them.....obviously tweak on car!.....

Jets are 56P and 63Sec with a 6.5PV.......maybe primary Jetting is too High?  but that would confused me only cause those came off a 1.14 2bbl autolite.....this is strange!

Mine were 47 p  and 56 sec And was too rich  , Lean a little and changed the     corroded idle mix screw .
Please can you explain  "  front Main Idle screw is backed off all the way (no longer in use) . 
in the 4100 are the mix screws  2 pieces with springs ?   why  is no longer use?
thanks 
 

Did you take the butter fly plates out of the shaft and put them back in? If so the plates could be in the wrong position. Hold the carb up to a ight with the idle screwed all the way out and look through it you should not be able to see hardly any light through it. If so readjust the plates till they both close all the way.

Thanks Hudg and Jon........

I did recheck both these things multiple of times.....I ensured the beveled edge (top and bottom) were installed correctly and 0 light enters when both are closed off!

there must be a Vac leak at the flange!  very peculiar.....now the intake is a Aftermarket Aluminum which came off a 80's 302, so perhaps the mount is slightly different?  going to try a widened walled spacer on Sun.....see if that rectifies everything...........

You can go hunting for a vacuum leak with a can or carb cleaner.  Just start spraying it in suspect areas.  If you get a change in engine speed you've found the leak.  One place to check, especially on older carbs, is the throttle shafts.  If the holes are worn they often leak right there. 
 

A lot of those shaft bushing deals have to be reamed to fit, or are universal, so I'm always suspect.  I never understood why they didn't use seals there.  Some carbs I've seen over the years do, but not very many. 

Thanks again guys......For starters, did find VAC leak on the base -------- AGAIN........
John Richard nailed it on the head with these factory jerks making these great factory FORD/Holley Carbs but they DO NOT play well with anything AFTERMARKET......its idiotic!...

2 spacer plates later and Still same leak.....posting pictures from phone video----------No solution comes to Mind!!!!!! anyone know what to do?

uploading 2 photos showing Vac Leak (big gap is rear and smaller is front) and 1 photo showing new spacer (take note of how wide the walls are - chosen carefully to try and eliminate the vac leak)





 

You may have missed it but I suggested you could turn the factory space up side down to temporarily get you by, but the bores are tapered to help slow the A/F charge so the fuel doesn't drop out of suspension when it enters the plenum.

Weiand makes aftermarket dual plane manifolds that work with Autolite carburetors and that really is the best solution, otherwise you'll have to stack another spacer between the manifold and Ford spacer.

Or make one out of like 1/8" thick aluminum.  I'm guessing hood clearance may be at a premium.

When I was running a 4100 and a edel performer manifold I filled the back side of the Ford spacer with chopped FRP and used a .080 aluminum spacer to seal the leak.
 Now, the Performer RPM Edelbrock has added material on the carb base and the 4100 does not leak in that area.

M1Mustang69 wrote:

was hoping filling the Void wasn't necessary, is it still!??

Perhaps not, as long as you can be sure that the heat shield will seal properly.
 I  did not want to chance it and tear every thing apart again.