Conversation Between 1983F1503004x4 and jruggles

Like I mentioned, take a look at the Inline-6 forum that I posted a link to. You can make a water heating plate to go on the intake that will bolt right to it. The 390 can also be tuned to work with the 300. The reason I suggest a 4bbl bigger than a 390 is because a lot of people have issues tuning them and getting them to run correctly. There's a thread in the Inline-6 forum right now about a Holley 390 with tuning issues.

The C-series will work fine with the 390, and will run fine with the primaries facing the radiator and the secondaries facing the firewall. An open plenum intake works different than the DP intakes.

When heat is taken away from the intake, the motor will draw in liquid fuel, which is unable to be burned. For fuel to be burned and metered in the correct amounts, the motor has to draw in vapor. Running water heat to the intake essentially boils the fuel and keeps it in a vaporized state.

Check out the Inline-6 forum:

Ford Inline Six, 200, 250, 4.9L / 300 - Ford Truck Enthusiasts Forums

Hello!

I just replied to your thread on your pickup truck in the 80 to 86 forum.

Like I mentioned, all motors require the intake to be heated. On V8's they use coolant passages in the head or passages for exhaust to flow through and provide this heat. The 6's suffer because the carb and manifolds are mounted on the side of the motor in open air. The factory manifolds were bolted together so the exhaust manifold could supply heat to the intake. This is why the tailpipe connects directly below the stock carb/manifold.