340 stock manifold to header adapter question

I'm just about ready for 1st fire up, engine is on run stand. Running the 340 hipo manifolds. I have this "header back" kit from Summit
Summit Racing SUM-680144 Summit Racing™ Header-Back Dual Exhaust Systems | Summit Racing
Is there an adapter that mounts the stock manifold to 3 hole header plate?
Thanks
Steve
Steve, try Nappa if you have one close or, Princess Auto. They have a lot of this stuff.

Cheers!