Hi!

What is the difference between the 390 and 428 engines?
I don't know what type of engine I got.
I have some numbers here:
- intake manifold: C9AE 9425-B
- water pump: C9AA- 65F5
8505-A

1., Cylinder head: 9A23
2., Cylinder head: 9BB

Is there any lookable difference between the engines?

Any information about my engine is welcome!
Thank you!