Absolutely there was. But, he is starting in the wrong place. Carbs out of the box are generally very close on main jets. Some one else led him to the oem setting for jets for which he should return to if they have been changed. Jets are more dependent on the carb itself and atmospheric conditions then what is setting under it. He complained about drivability problems, said the plugs where a good color (althought reading plugs is an art so he probably is not seeing many things) and said that it had been a long time and he was rusty. Hence, as you put it, carb 101. What carbs and crate motors for that matter generally have against them out of the box is proper adjustment. Which is where I think he should start before trying some magical modifications only to see no improvement, run out and by another carb, and continue to be frustrated because the initial setup was still not done. Eliminate the simple and free stuff before he starts looking for a problem that may not exist.
You did bring up a very good point though. Once he does try and set up the main jets, he can't do it sitting in the driveway. Even the carb 101 that I gave him will need to be tested on the road and final adjustments made. But assuming the carb is not defective or in need of repair, if he carefully sets it up, I would be willing to bet he will be much happier then he is now.