[Oldsguy]

First you need to put your timing back where it was. If you can remember the approximate location the distributor was in do that. You can't set timing while the choke circuit is active, you engine has to be at idle/warm condition to set timing. After that, I believe your problem would be the choke circuit. It's possible that both carbs had a mal-adjusted choke. When the engine is cold you should slowly pull the linkage all the way back (or push the accelerator pedal down). It is better to move the linkage from the engine bay, observe the top plates on the front (four barrel carb) or just the top plate (two barrel carb). It/they should close all the way with a small crack left between the plate and the throttle bore of the carb. If the plate/plates don't do this then the initial choke setting is off. Usually the choke on a Rochester is activated by a round bi-metal spring located in a round housing on the passenger side. There will be three or four retainer screws holding a black colored plate. Loosen, don't remove these screws, this will enable the plate to rotate, there is a slot in the middle of it, use a large flat blade screwdriver to twist it in the direction marked "rich". Be careful, if it doesn't move easily you might break ths slot. In some instances you have to totally remove the screws to see if it is jammed up with carbon junk, but don't do that unless you absolutely have to, it's not to easy to re-assemble. Anyway, you should see the choke plate move when you rotate that black colored plate. But you have to have the acclerator linkage pulled back all the way too. If you can reach it from the passenger side and do it with your off hand. If not you will need help. Adjust the choke so there is just a crack of air space as I described earlier. Then tighten the screws. This is all done on a cold engine that hasn't been started. If this doesn't help you may need more adjustments to other items like the choke pull-off device. This lets the choke plate open a little temporarily when you "hammer" the gas pedal during driving conitions when the choke cirucit is still active and the engine isn't warmed up yet. But that would be later. Just set your choke first and see if that helps. I hope so. Good luck.