i have recently purchased an '81 22R from a guy, to put into my '87 4Runner. the engine has approx. 140k, and no real issues. of course, the 22R is carbed, and the now not working 22RE is going to be replacing it. i understand a new timing chain wouldn't be compatible, along with a lot of other parts. are there going to be any problems that can be identified beforehand?
if you ABSOLUTELY needed to get it going, the cranks and rods will interchange.