A passenger engine will be fine to use, but you will need a truck bellhousing and front engine mounts, as they are truck specific. Not sure about the clutch fork. The throwout bearing won't be a big deal, as you'll want to use a new one anyway. You can get that from the parts house. As far as the transmissions are concerned, the 3 speed manual trans is the same between car and truck, so that won't be a problem. The only difference is a minor bolt hole difference in the mounting flange. On the trucks, the 2 bottom bolts are threaded, and the bolts go in from the inside of the bellhousing. Passenger is opposite. This isn't really a problem though, simply use bolts and nuts on the bottom holes.
You'll also need to get the truck throttle linkage as well, I beleive they are different.
