looking to purchase aftermarket serpentine pulleys that have the same offset as the merc racing HP500 and up blue billet pullies but prefer to buy aftermarket. Does anyone make these?

The billet pulley sets are available from CPPerformance and probably Trick Marine. They serpentine kits are about $600-700.

I wonder if its a import or March is making them?

look around

http://www.marchperformance.com/index.html

They also make the cast valve covers for alot of the venders
http://www.wysco.com/autoparts/autoparts-03.asp

http://search.store.yahoo.com/cgi-bi...2Fnsearch.html

import stuuf
http://www.tdperformance.com/pdfs/66-67-Pulleys.pdf