will this work??
hmmm well from what i understand the head on the b20 is almost the same as the b18b. but it also depends on what b20 you talkin about, the b20b…or b20z? the b20b is from older crv’s and have less agrresive cam setup…where as the b20z is form the 99-01 crv’s and have a better cam’s from what i hear. So in theory if you put it on a b18b you might not notice a big difference , but on a b18a you may notice a slight diffence. but if your askin if it fits yes it will. But in IMO not really worth the time because of the little youll gain from it. I hope i make sense. 
yes it fits. I have a JDM b20b head on my car with '96 LS cams in it