Quote Originally Posted by boostedb16
what do you mean about the stud holes
the B16/B18c-R/B18c5 head is shorter than the GS-R [B18c SIR-G/B18c1]...therefore the GS-R header will work on the B16/B18c-R/B18c5 head but may have problems getting the B16/B18c-R/B18c5 header on a B18c SIR-G/B18c1 and still clear the oil pan. Makes perfect sense right?