Paul.  The Blue Thunder intakes do have the heat crossover capability if it’s deemed that is a must.  But I’ll reiterate that once an engine is fully heated, that exhaust crossover is a detriment to performance and especially if the exhaust flow continues to be restricted to force exhaust through the intake manifold.  In a perfect world, there would be a valve on each side of the intake to close that channel once the engine is heated but that would be more of an issue than the oem flapper valves in one side of the exhaust that helps to force heated exhaust through the intake manifold.  Those flapper valves are an issue all by themselves after they get some age on them.  If the heated flapper valve isn’t closing properly on the exhaust when it’s cold, then the full benefit of the exhaust crossover passage during engine warmup is not being capitalized on anyhow.

 

But now to touch upon the chokes.  The 60’s 292 intakes do not have a provision in the intake manifold for choke coil heating.  The heat source for the choke came from the exhaust manifold instead.  I have some ECZ-B 4V intakes here that also do not have the choke tube going through the intake so I’ll assume that many of these came off of the big trucks.

 

Many of the Sixties Ford V8’s used the exhaust manifolds for the automatic choke heat source.  The exhaust manifolds had a cast chamber in which air could pass through to be heated before entering the tube going to the carburetor.  My ’61 Fairlane with a 292 had an insulated and covered tube going over the passenger side valve cover for the choke.  My ’62 Convertible with a G code 406 had a similar cloth covered tube going over the drivers side valve cover to provide hot air for the choke.  Electric choke coils are a way of life now for carbureted engines.

 

Here’s a picture of the FE 3X2 setup with the automatic choke pulling heated air from the drivers side exhaust manifold.

 

Lorena, Texas (South of Waco)

Here are pics of a Blue Thunder with a welded up exhaust heat riser ports and the Mummert intake as provided with no heat riser passage.  Welding up the port in the BT intake eliminates the need for putting shim stock at the gasket to block the port and also allows the intake manifold gasket itself to sit more square with the mating surfaces and not bow the intake up in the middle.

  Blue Thunder Intake

  Mummert Aluminum 4V intake

Lorena, Texas (South of Waco)

I wonder, does John routinely offer pre-machined examples for those with milled heads? While quite a bit of latitude likely exists, providing head thickness & gasket specs. when ordering would make for a more perfect seal.



Also, I wonder why the riser block-off area isn't recessed/machined to accept the raised gasket section, since a flat/unbowed seal area would seem desirable? I assume no one makes a flat gasket?

6 VOLTS/POS. GRD. NW INDIANA