Hey guys can anyone tell me if the EMI thunder exhaust manifolds are a direct swap and bolt up to the factory manifolds on the 500hp Carb models that had come with the Gils/Hardin/Perf mercruiser manifolds? Reason I ask is my boats a triple and needing to replace them all, and didn't know if the riser bolt pattern would match.

Thanks in advance, any input would be great.

EMI manifolds won't bolt up to a Gil risers.
http://www.diamondperformanceparts.com/home.php?cat=255

Do you know if the Dana manifolds would or are the Hardin the only option? My boats a triple and has stainless marine risers all fabbed thru hull. I'm not wanting to redo all the risers. Thanks for any insight!

Hardin is your only option, http://www.diamondperformanceparts.com/home.php?cat=329