OK- - - -the website just ate a long reply! If the heat passage in the manifold is open, there needs to be a functioning heat riser valve installed in the passenger side exhaust pipe. The only time exhaust heat under the carb is needed is during warmup, and without a heat riser with a functioning bimetal spring, there won't be enough exhaust gas moving under the carb to do any good. Once the spring heats up, flow under the carb goes away, as it should.
The firing order and the extremely restrictive exhaust on air cooled VW's kept the exhaust flowing, and that carb was so high above the engine heat it needed a hot intake all the time, especially in winter. Small block Chevvies are not VW's!
Jerry
