If only "You Tube" had existed back in the 70's when I was struggling with algebra. I made the assumption that if someone was interested in a 70 Series that was already located in the States, they would have the ability to locate it on Ebay. It is after all the only 70 Series currently on Ebay Motors.
my advice? try to take care of it, and drive it until it craps out. when (not if) that happens, don't throw away good money after bad, and look at replacing the engine entirely as opposed to dumping money into a crappy engine. the LJ 70 is a great little unit, and there's lots of feasable options for replacing the engine.
for the price of fixing a blown 2LT(E) head, one could just about swing putting a rebuilt 22R engine in its' place.