How bad was the damage? replacing a head gasket on a 4cyl isn't a huge affair. Clearwater still makes a non jetvalve head last I heard. Others who have the 4cyl trucks will be more knowledgeable on this. Rebuilt engines and JY replacements are really a gamble because you don't know if your getting a good one or a timebomb.

Richard E
1989 Montero - Stock-ish
1989 V6 Auto Raider - 5.3 Vortech Swap.
1987 Mitsubishi Starion 2.6t, soon to be 3.5
1983 Honda XL600R