Autolite 2100 conversion jets

[wsa111]

You are just wasting time & energy till we know the basics of the engine. Cam, static compression ratio, cranking compression.
Since you stated the distributor is stock 68 vintage, it needs to be checked out on a sun machine after all the above is known.
Since the carb in on an adapter you are only getting 50% benefit of the carburetor.
No further discussion is needed since all the above is just guess work.
Hate to be negative, but without the correct tools its just a stab in the dark.

 

[xctasy]

You really need a CO meter and help with making sure your idle Carbon dioxides and actual air fuel ratios at cruise and wide open throttle are okay as wsa111 says.

Before doing that

Check that the car doesn't have a exhast full of condensed water. Run it for 10minutes. Then source new idle screw needles and a new float needle and seat.

Then recheck float level.

Its not uncommon for basic parts to wear, or there to be an air leak somewhere. Water and soap solution sprayed on the gaskets, look for leaks. Or a propane torch unlit, look for engine idle flare up. CHECK GASKETS.

Vac at idle is good. Are your thermocator and air pump blankoffs leak free?

46 jets sound pretty good to me, a 166 hp Falcon 221 cubic inch with a 350 Holley, a 2-bbl 1.18 carb if you like, would run 53's or 56's, so jetting down is not what you need to do. Two 46's are enough to make a good amount of hp, and are not too rich.


Hang in there.