your throttle bodies are the same size, why woiuld yuou want to put a b16 throttle body on a b18 intake manifold? seems kinda pointless to me....it would make more sense for me to do it on my d16 b/c i will have a 4mm bore increase. unless your throttle body is not functioning correctly, leave it alone...there will be no throttle response increases if you do change over.