Chevrolet used exhaust heat on virtually all of the 206,216,235 and 261 engines. That is good enough for me!
The only water heated intake ever made to use water is the Edmunds brand of intakes. Virtually all of the others are set up to use exhaust heat. Fenton did offer two choices for exhaust heat, the two tubes running one from each header to the intake manifold heat plate. The other choice is the type of Fenton headers that had a heat chamber built into the back header which supplied continious heat to the intake manifold. I don't think a person could make an argument for too much heat to the intake. One thing that I do know for sure. When using the two tubes, you are mixing the two sides of your exhaust. The result is a deadening effect on the sound of the famous six cylinder exhaust. The effect is noticable and just really deadens the sound. Tom Langdon mention that to me years ago. I decided to use the two tubes, but welded two pipe nipples on the front exhaust pipe just below the flange, one pointing downward and one pointing upward. I then ran a tube from each so that the exhaust would enter the upper one which was pointing up and exit from the lower one pointing down. I installed them on the back of the exhaust pipe so they couldn't be seen from the side view of the engine. This stopped the left and right side exhaust from mixing and keep the crisp sound of the six cylinder engine. Later I found a pair of the old style Fenton headers with the rear heat chamber built in. I now run that style on my 261.
In both cases, I never encountered any heating problems. It always stays hot all of the time - continious heat, like it is supposed to be.
Joe
