So the vibration goes away when you coast in neutral at 40 but will come back when you gun the engine in neutral?

I'd look at your flywheel along with the other things mentioned.

Last edited by Otto Skorzeny; 11/27/2022 9:24 PM.
1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)