Yes I have built a hybrid 20/22R. And I have also built plenty of 22Rs and 22REs. Have you ever built a good 22R
20Rs have a 80/81cc combustion chamber, early 22Rs 82/83cc. 20R valves measure 43mm/intake 35mm/exhaust, 22R valves 44.5mm & 36.5mm. By putting a stock 20R head on a stock 22R block you have decreased you combustion chamber by 1 or 2 cc's, but you now have smaller valves. I'm sorry but decreasing the combustion chamber by 1 or 2 cc's and DECREASING the valve size is not gonna give you a 30hp gain. If you believe that, then you can probably get at least another 20hp just by using a K&N air filter. You might even squeeze an extra 15hp out of it if you go get yourself a chrome plated import muffler!!...... Don't fool yourself .
If you were building a highly modified motor from scratch, and never wanted to run EFI then a 20R head is a good option. But putting a junkyard 20R head on a high mileage 22R block is not gonna be worth the effort. Ya'll also failed to mention that a stock aisin 22R carb will not bolt up to a 20R intake without an adapter plate, and you have to re-route some heater hoses. Also beware that the majority of 20R heads do not have anywhere to bolt a mechanical fuel pump or power steering. I think '79 & '80 where the only 2 years with the FP and P/S mounts. This is an awful lot of trouble just to decrease your combustion chamber by only 1 or 2cc's. Yes, I've heard that a 20R head will flow more air, but with a stock head , stock cam, stock valves, stock exhaust manifold , what are you achieving? 79coyotefrog is trying to tell people you'll have this tremendous hp gain by swapping all stock parts. This is simply not true.
Those of you who "estimate" you have a 150+ hp 22R. Have you ever drove a 3RZ. A 3RZ has around 150hp stock. I have seen very few "built" R series motors that will even compare to a 3RZ. Hmmmmm?
