The s52 head is the same as the s50 head. Unless he's got an s52 motorswap, there is no gain by swapping heads. To fill you in, the '95 M3's came with the 3.0L s50 motor. The 96-99's came with the 3.2L s52. The heads are the same. Hell, even the blocks are the same, except that the s52 is bored...