I'll come back and read everything later but some highlights from my memory
stock 20 R carb is 190 cfm
stock 22R carb is 325 cfm which makes the 3236 weber a perfect replacement but the stock carb out performs the weber for offroading in tuned correctly
20R combustion chamber 75cc early and 81cc ish in 79 and 80 and up.
22R is about 85cc also
22re 55cc
22RET is also 55cc (pistons are different)
stock 20 and 22R cams was around 390 and about 190 duration it started off about the same ramp as the 215* but since emissions sucked the close side drops off sharply
My setup has one thing I really love about it. when pulling a heavy load once my soninlaw and daughter were following me and she called me on the cb and said "Dad, do you know that when you shift a 3 or 4 foot flame shoots out the exhaust?"