'53/'54 Exhaust Manifold - valve

[noevalley]

I have just removed a '53/'54 Exhaust Manifold from a non-Corvette Chev. The "butterfly" valve is missing. Can these be replaced? Are parts available?
What's the bad news about what this has done to the value of this item?
Thank you.

 

[RonJ]

You used to be able to buy heat riser kits for the old 235's and 261's. If I remember, the kit came with bushings and a new spring.

I'd think you could find a useable shaft and butterfly at an old bone yard somewhere!

Ron ...

 

[noevalley]

Ron, thanks for the feedback. More news. The opening (square one) over the heat riser was welded over sometime in the past. That is, not possible to access any more. Guess two things. One - engine takes longer to heat up, and, two - value of this as an Ebay item has been loused up. Any further comments?