Rough Idel Of a chevy 350
 

I have a 87 chevy and i just put a new 350 longblock in about 6 months ago. I have added a hei mallory distrubitor and a new edelbrock 600 carb. I have a ruff idel now and caint seem to find out the problem. Can sum one help with the rough idel?

Couple of ideas:

If the roughness smooths out as rpms increase, check for a vacuum leak.

Pull the plugs and look for fouling.

he motor ran smooth before you pulled dist check that.
might be a tooth or 2 off.
I would remove all plugs and turn motor till #1 is at TDC
then reinstall distributor and wires.
but first double check your firing order ( could be as simple as that)
firing order here:
http://www.boxwrench.net/specs/chevy_sb.htm

You have adjusted the idle mixture? What intake is on the engine? is it a stock intake with a adapter so the edelbrock carb will fit? Need more details.