You have a performer intake on a 418 with trick flows with a 650 carb? I’ll like to change my previous answer, it makes really no difference what camshaft you put in that engine. It will never be what is holding it back.
:lol:
No changing answers!
I don't believe the carb is as bad as the manifold though for airflow restriction.
I would love to see a dyno graph of the drop off above 4000 rpms.