1978 25 hp Evinrude question

[Johnson18hpfd]

I am looking for information regarding the gas tank on a 25 hp 1978 Evinrude. Does this motor operate on a pressured or vented gas tank? Also, is the lower end from a 1964 18hp Johnson interchangeable? It does look like the exhaust housing is.

 

[F_R]

Re: 1978 25 hp Evinrude question

#1 Vented

#2 I suppose so, but haven't actually done it.