Inliners International Forums General Discussion Hi Performance general question on 12 port heads

I have seen a few 15 bolt 12 ports on 18 bolt blocks, including those by Jerry Weigt, Hank Lawshe, and Keith Young. As I remember (it was quite a while ago) most head bolts line up, and the ones that don't (1 or 3?)in the block are plugged and redrilled to match. Only 15 head bolts are used.