360 engine vibration

I like to see these cars set up the way Ma Mopar intended them to run.

You say you put HEI on it, OK now you need to run down this whole thing. Spark Plugs you Selected, Are you Using Platimum Spark Plugs with the HEI, or are you running stock mopar recomended plugs for the mopar brain box gapped at.035" ths. Or are you running a .060 to .080"ths gap on your Platimum Plugs. Got to get all of this stuff mached up right for the technology that you are using. Once you are sure it is right, then move onto the next thing.

Next thing, these carburetors fill up with sediment and corrosion especially after sitting for 4 years, and really especially if you had it stored with ethanol gasoline for that 4 years. Ethanol gas goes bad in 2 months, it draws so much moisture it is crazy. Want some good 90 octane non ethanol gasoline to start with.

I would take that carburetor off, disassemble it, run it through you ultrasonic cleaner with your favorite solution to get all the internal passages cleaned out. Put in the new needle and seats so the rubbers are good, new accelerator pump same, new floats are a good thing too. Just this alone I am sure you will notice it running much better than before.

Keep working through it.