I have a 460 i'm putting in an f150. I am bolting it to an np435 and am having a few problems. I got a flywheel from a 390 and although it bolts up okay, the clutch wont bolt to it. Its a 12" clutch and the bolt holes on it are spaced about 1/2" to far to bolt to the flywheel. Also, when i hold the clutch disk up to the flywheel, the springs on the clutch hit the flywheel bolts. Does this mean the flywheel has been machined too far and i need a new one? And do i need to get an 11" clutch instead of a 12" one? Or do they make flywheels drilled for a 12" clutch? Thanks for any help.