Just started her up after a long winter and AOD swap. Problem: 93 octane gas just put in. BAckfirinjg like crazy (wevery sec or 2 with open headers) No vac leak anywhere. Why???? How do you adjust lean/rich mixture in edlbrock 600 carb? HELP!!!
It could be bad fuel. Fuel usually only has a certain shelf life. Try putting fresh fuel in the lines and see how it goes. Might take 10 or 20 mins to clear up.
I haven't hooked up the exhaust yet. quots are $700!!!! Doing it myself. Could I have always had the backfire but never noticed it with the exhaust hooked up?
Put new gas in it and still the same. Ran for 20 min.