1960s Exhaust heat control valve aka Heat Riser

[R Simone]

The heat riser on my 69' was in really bad shape when I rebuilt the engine - seized, leaking.  I told myself I never wanted to work on the exhaust again and spent the money on a new reproduction (I looked and don't remember being able to find a spacer for it as mine is beveled on one end).  Anyways it works fine, but for what it's worth I don't notice any difference whatsoever and the new one actually seems to tick a tiny bit as well until it heats up. I also got some "Genuine GM Fluid 88862628 Rust Penetrant and Inhibitor" as recommended by site members as it's specifically made for the application.

[35-709]

The "tick" may well be an exhaust leak (gasket?), if so, it will get worse over time.  Very typical for an exhaust leak to make a ticking noise and then go away as the metal expands as it heats up and closes off the leak.

[Suntuned]

I purchased a blank from Russ Austin for my 1964 Fleetwood to replace the valve, I also purchased blocked off intake gaskets from Olson gaskets for the exhaust cross over on the intake because my intake had a small crack in that area. Then i install an electric chock stat on the 4GC Rochester. When the engine goes back in after the dyno time I'm eager to see how well the chock performs with out intake heat @ warm up.