actually i never have rebuilt 22rs my experience is with vw motors, for sure well developed aftermarket cams are better performing, but there is the trade off of fuel milage. and longevity and the block was not bored .50 over, its actually .020 over the pistons have a marking of .50 which is next size overbore i think. i just found out the head is a china casting, the valve seats on the exhaust side was so pitted in only 20 k miles. I'm torn if i should do a mild port job or just slam it on my current block in the truck get it running and build up the other one with a Toyota head slowly.
does anyone here have a Chinese head that has lasted a good long time?
also the turd that rebuilt the motor last tightened #3 exhaust to .005 thou and it wrecked the cam and the rocker arm!!
lucky my bud has an extra 22re cam EM . ill go to pick-a-part on sat to find a used rocker.
bumbed out that i have a 
aftermarket head.
piston markings are in mm
.5mm is the same as .020 inches
in these engines the power is found in the head and cam, the 22R has a long stroke so they designed the cam to make the engine run out of breath before it ran the rods out the side of the block
ive been running a LC engineering stage 2 race cam for about 6 years and it didnt give any problems with mileage, in fact my fuel mileage didnt change at all, but i REALLY noticed the power, running 70 mph on the interstate, then drop the foot to the floor and it runs up to 90 (before i went to 35's) havent even tried to get THAT fast since the wreck, (not related to speed) i can easily get to 80 though
the cam i suggested to you is milder than the cam i run and can be put on any 22R or 22RE
