Type R engine has mark or printed B18C5 by the block and the cylinder head by the upper header would be printed with PR3-4. GSR - B18C - PR3 - 3. This how i spot if it is a type r or gsr for acura but on SIR {B16A,B16B}, Im not so sure.But i also heard that they hav similarities on parts..So there!, Hope it help you..