I searched and found this post on the transition spot and would like to know if this could be my problem.
http://67-72chevytrucks.com/vboard/s...ight=quadrajet
I have a 1974 Chevy C10, 103,430 miles and a 454\TH400\3.73 gears that hadn't seen much love in years. It ran like crap and the MPG is 6.9 on the highway at 65MPH. The truck flooded easily and the warm idle would vary from day to day between 800-1100 in park and 400-600 in gear.
Last weekend I rebuilt the Q-Jet but didn't notice or change the jets. After the rebuild the engine really came alive. It has an broken old style choke with the heater on the intake but it doesn't seem to cause any trouble once it's warmed up.
The problem, other than the 6.9MPG is that it runs rich even with the idle screws out at 2.5 turns each. If I turn them in it gets the shakes.
To give you an indication of how rich it's running my eyes water and today while it was idling in the drive way I goosed it a couple of times from 800RPM to maybe 3,000. The dual exhausts are dumped under the bed and point down. After moving the truck I found some very black-sooty spots where it had been parked.
Timing is set to 12BTC and I have a curve kit with medium springs in an HEI. At 2000 RPM the timing is too far off the mark to know exactly where it's at. If I had to guess I'd say 24'ish. I know that's not much help but it's all I have right now.
Does this sound like a timing or carb issue? I need to make a 450 mile trip with it in a couple of weeks and would like to get maybe 10 out of it. I don't know if that's possible but I am certain it's still running rich.
Thanks!
Randy