170 motor

I have a 63 Plymouth Valiant with a 170 motor in it. I discovered recently that the exhaust manifold broke from age in 2 places. My questions are: Will a 225 head bolt up to a 170 motor so I could use a header? I read a bit about others talking about stroke difference in the engine. Whats this mean?

If not then who makes a 170 header to go with the new intake manifold that I plan on using?

I read here about using a 4bbl intake vs a 2 bbl intake for the economy feature of the 4bbl not working all the time. This makes total sense.

Sorry for the simple questions but I come from a diesel background and this is my 1st foray into gas cars in 30 years

Cheers,

peter