GM LS Cylinder Head Cross Reference

We've tried to boil down the GM part numbers, casting numbers and other LS cylinder head information into an easily usable (and ideally definitive) cross reference.

Note that we're not perfect and some of this data may not be perfect so use it for what you will. That said we use much of this internally as we're applying our LS head porting profiles to customer heads and we'll update it accordingly as you give us feedback or we discover new oddities.