Remembering that I know nothing about the 20r and little about the 22re couldn't you just take a 22re manifold and have a machine shop adapt it to the 20r head? Or are they that much different?

(aka suprathepeg, aka Sean)
89 v6 SWB truck "BLACK BEAUTY" EB valves, P&P head 30 over.
95 FZJ80. Lifted. locked and rollin on 33s (my dream machine)