tryin to break in new engine, ruff idle

Since you have multi-meter OHM every spark plug wire and they should be close to each other...disconnect at cap and at plug and ohm test each one,of course plugging them each in while going to the next...
Start with number one and you can double check your firing order.

You can get hiccups and back fires with a lean condition as well...
Vacuum leaks..
Did you set your 2 air/fuel mixture screws.
They are on each side of the metering block behind your front fuel bowl.
I turn them in till they seat lightly and back them out 1 1/4 turn each.
You can fine tune it after breaking in your cam!!!!
You need to break in that cam before anything else.
Try to do all your diagnose without continually starting it.
Here is a Holley link to your Holley.
I am guessing it is a Holley 0-1850 universal 600cfm
List number is on air horn on front of carb.

http://www.holley.com/data/Products/Technical/199R7948-5rev2.pdf


TXDart