Easily... well that kind of depends on your skill level.
The rear axle on the '78 is wider than your '65 and the spring perches would need to be removed and replaced with the 1963-1966 style.
What engine is in the '78? Original, I6, V-8?
What transmission is in the '78? Original, automatic TH350, TH400, stick shift 3 speed or 4 speed, column shift or floor shift?
All these questions would need to be known for us to help in any detail.
You could also swap the entire front suspension in if you want, just depends on how much time and effort you want to put into it.
