Engine now has hesitation.

[parrisc19844x4_468]

Some history, the engine is a 468 with heavily camed with a Holley 850 4150. Timing is set to 18%. It has a Accel HEI.
This was swapped into my 84 Scottsdale very tired 305. All was great until I realized at idle I have very little breaks. I put up with this for about 2 years as most of the time I drive only in the open county and brake were good as long as I had some vacuum. On to the problem. To fix the no brake at idle problem, I ordered and installed a vacuum reserve canister from Jegs. That fixed the brake at idle problem but created a real hesitation from the engine now. The engine runs great otherwise, no back fires in either direction, starts right up, idles good. It seems like it sort of cuts in and out when accelerating, once I reach cursing speed of 60 -70 mph all is well again. So being a problem solver at work, I did the same thing to diagnose issues here; I backed out the last change that were made, which was to remove the vacuum reserve canister. To my surprise the issue persists.
The only thing I thought was odd, there is no vacuum advance hose attached but then again not sure if that is needed with this engine. Maybe it had fallen off or got misplaced when I was installing the canister. I checked for vacuum leaks around the carb but didn’t find any. Any ideas?

[clapage6]

hmmmm. How is your stumbling in these scenarios?:

Stab the throttle from idle and accelerate quickly to cruise speed
very very very slowly ease on throttle up to cruise speed

sound to me like this could be a combination of accelerator pump/mixture screw adjustments/ and secondary tuning.

is this a double pumper? dual metering blocks? and vac or mech secondaries?

[clapage6]

can't figure out how to edit my first post. anywho. something quicker to try before the carb would be to increase your base timing a little bit and see if that changes anything. increase in timing should increase idle speed. which will allow you to close primary blades a little bit thus increasing idle vacuum also.

[KevinCowTown]

I don't know cr*p about cr*p but... the engine was running good, you put a vacuum accessory in, then the engine didn't run good.

I know you checked for vacuum leaks around the carb but there are freaking vacuum hoses all over the place on those years; touch one and a crack opens up (I just replaced, like, twenty feet of hose in my '85). Do you have a vacuum gauge? I'd circle back to the vacuum if I was you, check for a leak.

I hate it when some dumbass pipes in with stupid advice and I'm sorry to be the dumbass today but... that stumble... sounds like a vacuum problem I had; considering you worked on the vacuum system it might not be a waste of time to second check it. Take that for what it's worth (not much).