1968 Chevy Impala high rough idle

Hi Danny:

Sounds like a neat car. Did you replace the old fuel that was in it? Also, is it backfireing through the exhaust or intake? Finally, is the choke closing all the way when cold and opening after it warms up? NOTE: If it is closing tight, that is one problem. You should have about a 1/4" opening when it's cold and it should open fully when warmed up. Did you check for any vacuum leaks? Finally, what type of ignition does it have, points / condenser or HEI?

Also, was the car ever started while it sat and move short distances?

Let me know so I can better help. Muscle cars are my favorite!

Joe