I have seen some 400 430 motors that have a metal gasket between the carb and intake. When you rebuild the carb do you need that metal gasket and why is it there? Also on the drivers side exhaust manifold is a themo flap. When closed what does that do to help the car heat up or fun better?
The 67 400 and 430 used the metal heat shield under the carb, 68 and on do not. If you're worried about originality you can purchase a new repro one for a Camaro, but I don't think they really do much.
Sounds like the same sort of deal Chevy used up to the '70 models. It prevented hot exhaust gas from toasting the underside of the carb. Also prevented exhaust gas from going down the intake manifold. If you leave it out of a '69-older Chevy big block, the engine runs terrible.
Yes, it heats up the choke faster. It forces the exhaust from that side of the engine to backtrack through the intake exhaust heat crossover and exit the other side.
Crappy performance because of 1. restricted exhaust, 2. overheated intake manifold-leads to pinging, 3. overheated carb--boiling fuel out of bowl Possible cracking of heads/intake manifold because of excessive heat. Poor gas mileage due to restricted exhaust and fuel boiling out of carb.
