Everything in the bottom end is the same as early, dual row timing chain 22r except for the pistons and rings. I used pistons and rings from an outfit called Evergreen for the 20r because thy were made in Japan.
The head has different valves. Rockers, valve springs, guides, valve seals, cams and rocker shafts all cross over he same way from early 22r. By early I mean '81-'84 22r stuff in general.
Here is my recent 20r build...
https://board.marlincrawler.com/index.php?topic=102500.0I used some DNJ stuff. I don't think there is anything wrong with the bearings and hard parts but I have found the seals and gaskets to be second rate stuff.
