sup all. hopin you can help me with a little problem i have. just swapped a b18a block with b18b head into my civic. everythings runnin really smooth now, except for this vibration ONLY at 3k rpms. i cant freakin figure it out! im almost positive that its comin from the exhaust manifold. its not the heat shield though, its all bolted down, plus you can see that it doesnt move at 3k. any other parts that could be vibrating or anyone had this problem before? also, i don't think it really matters, but im using a GSR exhaust manifold.