Topic: Is there any difference between 350f and 400f engine casing

[yd72]

I am looking to convert my 350f into 400f engine capacity.
Is there any difference between the two engine casing?

Can 400f engine components fix into a 350f engine casing?   

[jessezm]

The 400f has 6 gears, whereas the 350f is a 5-speed transmission.  I would think that would prevent the swapping of internals without a lot of machining, which I doubt would be worth it.  You'd be better of purchasing an entire 400f motor and putting in the 350's frame if that's what you've got.  There's several here who have done it I think.