The ultimate older (22R,20R) 4 cyl to build consists of a 20R head, pre85 22R pistons, and post 85 22R block, rods & crank. Also put a dual row timing chain in it for better strength and less stretching. The 20R heads offer better flow than the 22R because of emissions reasons. When rebuilding your 20R head put 22R valves in it cuz they are bigger and you only have to grind the seats not replace them. I've had a 83 for almost four years now and I have been researching this pretty much the whole time. I picked up a motor from a junk yard to rebuild while I still drive mine, but I haven't finished it yet. A good place to look for your rebuild parts is eBay. You can find Weber carb kits and there is a guy from Oregon that sells the parts you'll need on there and his son runs a machine shop that does rebuilding. His username is engnblder or something close to that. This is where I plan on getting all my parts. Other places of interest would be
www.lcengineering.com and
www.northwestoffroad.com and
www.allprooffroad.com to find turbo kits and other performance parts. Hope this helped.