[sixt8bird]

Well I finally got the old bird fired up after polishing the tri power and changing the 1973 2 bbl center carb off of a 400 catalina to a 1968 350 2 bbl. The problem I am having is when you rev it the rpms take a while to drop and when you cover the center carb it will start to rev. The exhaust burns your eyes like a lean missfire. Covering the outside carbs dont change rpms at all so I know they dont leak. I think that I am running too lean as cutting off the air on the center carb makes it race up but if I cover it real close it will kill it. It does idle ok . So my question is, if I enlarge the center jets, does it have an effect on idle mixture or do I need to drill the idle air tubes. With the 73 carb, it ran pretty rich as I could fire it up without any choke and just drive even when around 50 degs and the exhaust had black residue after driving around for a while.I drilled the jets and the tranfer slots etc etc. The 1968 carb I have the choke hooked up so it fast idles until warm.My eyes are still burning from working on it 1 hour ago.