[MadMan]

To be honest, I don't work on carbureted cars often enough to know for sure. My suggestion is to make damn sure all the vacuum lines are routed correctly, and not leaking vacuum. In fact, make especially sure zero vacuum is leaking. This can be very difficult. Large vacuum leaks can be found with a can of flammable brake cleaner and a big pair of balls. Little leaks can be impossible, unless you put eyes and hands on every single thing that has vacuum to it, and even then, it's unreliable at best.

Me, I could just hook up a smoke machine to the intake and watch where the smoke escapes. And yeah, that would probably be MY first step. Second, I'd make sure the ignition timing is in spec. Need a timing light and a tachometer, which I think you have. Easy to get, if not. Which, btw, idle speed has to be set right before doing ignition timing. Ignition timing should probably also be double checked after everything else you do.

Valve timing is pretty unlikely to be off. Perhaps a little with an old, stretched chain. But a jumped chain is unlikely. Besides, you'd know. It'd probably run ok, but have very little power when driving, all the time, not just when cold.

The rest would be carburetor adjustment, which... I'm not sure about with the computerized carb. I'm sure your big fancy book will detail it well. I'd imagine there's some way of locking the computer in default mode, perhaps unplugging some sensor or such. And then likely turning a screw while watching a vacuum gauge. Hopefully. It might be more complicated.