I've done the 22R to 22RE swap. My 84 4Runner had a blown up 22R. I bought a salvaged titled 85 4Runner with a blown up 22RE for $375. I bought a rebuilt short block and took everything I needed from the 85 and swapped it into my 84. A friend of mine gave me a 22RE head that I cleaned up (media blasted), 3-angle valve job, and machined 20 thousands off to clean it up.
I took the entire wiring harness (both engine and dash harnesses), the EFI fuel lines, EFI fuel tank and pump, EFI ECU, and all the EFI stuff under the hood. I had to drill a 2" hole on the passenger side firewall to pass the engine wiring harness to the computer. I sent the fuel injectors off to get professionally cleaned (witchhunter performance). I cleaned every single EFI part by hand and ran every single bolt over the wire wheel on my bench grinder. It took me several months to complete but totally worth it.
Living at higher attitudes and driving some really high mountain passes with a carb sucked. I also needed my 4Runner to run at any angle since I was building it up to be a rock crawler.
Let me know if you have any questions about the swap.
Here's my buildup thread
http://board.marlincrawler.com/index.php?topic=14334.0