Well a little info here, Mike does not have any heads sitting on his shelves. He sold all his heads. Douglas is waiting for Mike to have some new heads casted. Hopefully by the end of the year Mike will have some casted.
I would say,there are not enough people interested for any Co to make some nice flowing alum,six cyl heads.
I could be wrong though?
If the inline Chevys were popular enough parts would be a lot cheaper. But there not, try & buy forged 307 Chevy V-8 pistons, those work in a 250 inline Chevy. Not available.