I would start with rechecking the timing. If it is within specs, try retarding it a few degrees and test drive. Keep doing this until it improves. If it only makes it worse, try advancing it a few degrees until it improves the test drive. You can also adjust timing to maximum vacuum, but with all of the modifications that you have made, it might not be the best setting for your application. It is important to get the timing right before you start messing with the carb.
Carl
