Generally speaking the small truck chassis can be a simple swap to get an older body on the road.... the down side is usually while the chassis is close it is usually not close enough to really be and look right. Most are often a bit too long or to short and too wide to locate the wheels properly.

So you either live with something that doesn't look quite right or you go thru the effort required to shorten/legnthen and narrow the really fit the body, then go about building proper mounts to bolt the body and fenders to. Depending on how good your original frame is it is often easier and cheaper (in the long run) to upgrade what you already have.