VERY WELL-DONE PRESENTATION

Just a quick question what did you do with underside of inlet manifold blank it off or leave as is?

THanks

Steven

Steven,

That's a good question. FWIW my guess is it wouldn't hurt to blank it off but not absolutely necessary since this closed chamber is only meant to [b][i]conduct[/i][/b] heat to the intake via hot exh air molecules (Warning --Hudson physicists amongst us may scoff and yell, "[b]that's convection!"[/b]).

My assumption is the new headers mount close enough to the intake and [b][i]radiate[/i][/b] sufficient heat towards it to keep it from freezing up.  

Hopefully someone who has actually installed headers chimes in here...

All manufacturers threw in the towel on the designs that circulate exhaust through the intake manifold by the mid-60’s. Too many problems. Instead they installed ducting and a thermostatic flap that allowed air from around the outside of the exhaust manifolds to be directed into the air cleaner until the engine warmed up.  And when carbs were replaced by fuel
injection, that went extinct too.  Good riddance.