Mopar derated the HP on all the 383 A body engines(300 or maybe 305 HP) supposedly due to the driver side exhaust manifold, so they said whistling
Me thinks that the 335 HP rated 390 FE Mustang and Fairlane GT and the 1968 1968 and up 428 ford motors ratings of 330 and 335 HP had a lot of input on Mopars decision on those A body HP rating work
Epecially the 275 HP 340 motors devil whistling

Last edited by Cab_Burge; 05/16/17 11:39 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)