Yes, the way a Stovebolt fires there is exhaust pressure alternating between the front header and the rear in even pulses. Someone mentioned earlier about carbon buildup in the tubes, wouldn't that be an indication of exhaust flow in the heat tubes?
All that being said, I've run Fenton's for years without heat and only see the need for manifold heat on very cold days (temps in the 30's), any other time after a warmup, all is good. After a short drive at outside temps of 50 and above, you really don't want to touch the intake manifold since it sits right above the exhaust headers and is bolted securely to the head - there's a lot of heat in that area guys!
I've got a metal fuel block that sits above the intake manifold and I'm concerned it's getting too hot, possibly bubbling the fuel. I'm going to try to isolate the block someway from all that heat.
