it all depends on what you are going with do some researh on the 22r (22re, 22REC)
You can find them often guys buy toyota mini trucks and put bigger motors in all the time so you can get a stock engine cheap i think some year corollas had the 22re.
If you want to put a used 22RE in it your only options are finding one from another 4runner, pick up or celica. Or you could put a new long block 22RE in there. Or do a conversion (Chevy, Ford, ect.) Either way $400 is a pretty good deal unless its a trash heap.