idle too high, makes undriveable

I have a 600 Holley on a 318 with high rise, i was having same problem, at the back of carb was a vacuum line, i guees it was for power steering which i don't have, i capped that hose connection off and went from about 1800 rpm at idle down to about 800.But sounds like either a vacuum leak or hose not connected, possible fast idle linkage needs adjusted