I got an exhaust manifold (Later type, round counterweight, lots of ribs) and had a question on the heat riser valve. At cold temp, as in sitting in my garage on the floor, the flapper is horizontal, completely shielding the carb from the exhaust gasses. When it gets warm, the spring relaxes allowing the exhauast gas to push the valve down, side closest to the motor slowly starts to drop down into the gas path, diverting it up to the carb stove, then continues to drop until its diverting all exhaust down toward outlet. Are all like this? I didnt know if they started horizontal. Also if the rear hole is leaking exhust like a seive, can you make a bushing and press it in or is it a gonner, a candidate for the old cut it and braze it closed?

Removing the heat riser is an unwise idea, see here. Sounds like you might want to keep looking for a manifold in less-worn-out condition, or find and install a new old stock heat riser rebuild kit.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

What do those run if you can find one? Does the hole wallow out or iis it the shaft that deteriorates? The one I have is great, my buddies has the blow hole. He was thinking just wireing it open and JB welding the hole until he can install my extra one.

Like Dan says- you can find heat riser rebuild kits for $40-$100 online and you can find new exhaust manifolds online or at parts stores for around $90.

I can tell you from experience that JB weld will not hold up to the heat of the exhaust manifold.

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Casually looking for a Clifford hyperpak intake for cheap.

New one for 90, sounds like a plan. Thanks

E bag has had them for awhile...$90-$100.

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Super Six Conversion Stromberg