I Once rebuilt a blown 4 cyl like that. First engine I did all the way! I had hard time finding replacement also. Think that is Jeep's own design.I got one from a truck and STILL had to rebuild that. Never did find running one. Lots of them in yards had heads missing, a bad deal I guess. The worst part is that darn cheap Jap manual trans. Aisin brand, with hydraulic clutch mutch like present American brands went to. Sure was cheap thing. Look into one of those "replacement" engines at car stores. Probly the best and cheapest bet. You will need to use many of your parts from old engine on outside to make it work. I spent around $1000 rebuilding mine, and you can pick up Chev V-8's for much less. I never looked into that myself at time.
