The 1931 Buick straight 8 I worked on in the mid-1970's had a manual heat riser. It also had an updraft carburetor, I believe. Buckshot, since the big rigs with the 283 ran more or less full throttle against the governor all the time, the exhaust generated plenty of heat under the intake withuot a restriction on one side.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!