360 SB RUNNING ROUGH NEW BUILD

This is a fresh built engine. All new parts.
Less than 1 hour of run time.
Broke cam in for over 20 minutes in Jan.
Ran great in short time start ups.
Then all the sudden it started running rough.
While it can run, I pulled spark plug wire # 3,5,2, & 8.
The running rough does not change.
When the others are pulled, the running changes.
What is the correlation between #3,5,2, & 8 timing?

I welcome any suggestions to help me thru this crisis.

Thanks,
SLD

intake manifold if it's a dual plane, one side feeds those cylinders. Probably a carb issue.

It is a original 70's model 4 barrel intake.
Does that it make it a dual plane?
How do I determine that?

Thanks,

SLD

It should be a dual plane. Last mopar 4 bbl intake I saw that was factory single plane was a 273 commando of 67 vintage.

Supercuda,

You were spot on.
The float was stuck on the left side of the carb.
Quick cleaning and back to running great.

Thanks,

SLD

Glad you found it