Piper PA-22 Tri-Pacer (N5839Z)

Sorry but that's NOT a TriPacer unless someone stole the nose wheel. It's actually a PA-22-108 better Known as the Colt.

A PA-22-108 is also a tricycle geared plane like a Tripacer. So it looks like someone did steal the nose wheel.But in their defense they did move the main gear forward so it could be used as a taildragger. You can still see the original rear main gear strut attachment point on the fuselage.

Unofficially called PA-22-20 but you cannot change what is on the registration. It is still a PA-22 Tri-pacer. To answer the question in the title that engine cannot be used in that plane. Pacer and Tri-pacers use the Lycoming 4 cylinder.
Tri-pacer had a 2 seat model called a Colt.This one is the colt. You cannot tell by looking at the front that it once had a front main because the lower cowl is swapped to a Pacer style for cooling.