340 manifold exhaust leak

[dustdevil]

hey guys i just put some 73 340 exhaust manifolds on my 318 now i have a rowdy exhaust leak on the driver side manifold..is it possible that the manifold is warped?

 

[bobscuda67]

Your 340 manifolds have a large exhaust port and your 318 is a small port head. You might have a port mismatch. Look on the manifold and see if there is an opening on the bottom.

 

[dustdevil]

i thought the 340 manifolds matched up with the 318? dang!

 

[dustdevil]

no there isnt an opening on the bottom of the manifold. i even checked to see if my heads had emission holes and they dont. someone mentioned that they may be warped?

 

[340duster]

Check to see if the manifold outlet is touching the head below #7 exhaust port. If they are smogger 318 heads, the machined surface below the exhaust port (where the air injection line goes in) may be keeping the manifold from bolting tight to the head.

 

[dustdevil]

it bolts up tight..but yea the manifold doesnt sit flat on the number 7 port.