I picked these up in a package deal. Part number on box is7007194. Part number on head is 3769974. I have a matching pair. I really don't know their history or viability of use (any good to use?) so I thought I'd ask. What were these originally for? They are fully ported/polished and marked Mullen. They have "360" cast into he head as well. I even have the original boxes which I think are cool. The only think I find odd is the intake bolt pattern is slightly changed . It can be reversed easily, but why do that in the first place? Anyone familiar with these? I'll try to post some pics. Thanks in advance.