I recently came across this matched pair of small block Chevy exhaust manifolds. My research leads me to believe that these are genuine GM castings.

 They have been smoothed in preparation for a ceramic coating.  The pics tell the story. There is slight ghosting of a number on one of the manifolds ending in .....901. This led me to images of 3797901 and 3797902 castings.  They appear to match these manifolds.  I believe that these were cast in the 1990's. 

These manifolds are a great alternative to headers. They breathe well, but will not leak, or throw off excessive heat. Authentic GM exhaust manifolds are  the highest quality casting that you can buy.   This manifold set has never been used.  No worries about cracking here, unlike older GM castings, or the cheap foreign sourced manifolds offered for sale.  

• These manifolds have not been ported, so you have a choice; stock or ported.  

• Promptly shipped via FedEx home delivery. 

• Thanks for looking.