Having problems getting my dual port engine to run. It is stock except for an extractor system. 34PCIT carb and no heat riser attached
Can get the car to start and run if i play with the throtle but it will not idle after a minute or so. If i increase the throtle slowly it will pick up and rev to about 4000, if throtle is pushed in fast it will stall. Have rebuilt the carb and searched for manifold leaks with water to no avail. Have even tried a different carb, same prob. Anyone have any ideas? Have i missed something? Is it icing? Manifold is getting cold but not as cold as i have seen before when these things ice.

You can eliminate the manifold icing up temporarily by removing the rear coverplate & buying/borrowing a good length of "donkey dick" & putting one end over your air cleaner inlet & the other into the heater box under the pushrod tubes.
I don't feel that's the problem as it seems too severe. Is the accel pump working OK? It appears there is no fuel for the low speed ranges. Check your idle circuit for blockages. I see you've checked for vac leaks I guess at the various flanges but don't ignore the manifold itself- it may be cracked where you can't see- eg into the heat riser tube. Can you get a spare that you know is OK?
Geez these probs are a pain because can't measure anything- you just grope around- good luck!!

Thanks for the suggestions. Hooked the heat riser up and fiddled with the carb some more, managed to get the thing to idle and run pretty well.