Interesting ; I know nothing about glow plugs , except they get hot , What if I installed 1 on the intake , where its tapped out for the vacuum ( windshield wipers etc. } power it up with a switch that could be turned off on the dash ....when every thing gets hot turn it off .....

I'm going to install the glow plugs (probably a pair) in the heat cavity at the bottom of the intake which makes no contact with fuel. Directly in the plenum will likely result in an explosion!