On my stock cast iron 502efi exhaust on the risers the water fittings are just capped off with a rubber cap and hose clamp. Do I do the same with the new Stainless marine manifolds and just use the water feeds on the bottom of the manifold and cap the ones on the risers or do I need to change the plumbing?

Stainless marine manifolds are plumbed with the water inlet on the bottom of manifold then out the forward top of the manifold and into the water bung on the stainless riser . Stainless marine is a dry joint manifold .

Ok so then I run the same feed hose to the bottom back of the manifold and then use the hose that came with exhaust to go from the front of the manifold to the riser?

Yes

Do you use any sealant on the three fittings or install dry?

Use a thread sealant like this or similar https://www.permatex.com/products/th...hread-sealant/

Thank you for the answer.