Briggs & Stratton Part #356777-3137-G1 ENGINE 18 HP

Hello everyone......just wanted to make sure I order the correct part before I re-assemble the #2 cylinder head assy. Can someone please confirm which exhaust gasket/flange I need to order. Looking at the cylinder head assy as it sits on the engine, it is located at the bottom where exhaust manifold mates up to exhaust port on head. Huge price difference between the two part #'s.....I remember on a similar application, either would fit ... just one was thicker? 
 


 
Part Number: 691613
 
or 
 

 
Part Number: 692074
 
Any help would be great......thxs.
 
JO