I would treat that ute the same as I would a KE10 Corolla. Nothing but a K motor. Get a 5K if you want, or a 7K-E at the very wildest. Most people tend to use a 4K, with 3K head, mild cam, different carb etc which can make for a good motor if done right.
Was this a Aust. delivered car? Can't remember seeing any before.