71' 340 air cleaner, choking out my little 318. WHY??

TrailBeast said

Air restriction from either the lid being too close (which I doubt) a secondaries linkage hitting the air cleaner base or the hot air door on the snorkel is closed.
Couldn't be much els.e.

Well, possibly a plug wire arcing to it. :D

Click to expand...

I took just the lid off, and it ran great. No snorkels on this one, just two hole lined up with the hole in the hood under the scoops. In the morning i'm going to run a nut down on the carb stud as a spacer ,then screw the lid on. I thought maybe someone had run into this problem with this particular air cleaner/carb combo.