ignition coil ?

Some coils run hotter than others.
Over 140 is too hot to hang on to for long. Metal cased ones run hottest. Hi-po metal coils should be run studs facing down, so that the transformer runs in the oil.
However, the more voltage you pull thru them, the hotter they will run; this is why you always run a ballast resistor in series with the power supply.
Furthermore, with a point-trigger, you ought not leave the ignition in the "Run" position for extended time,with the engine NOT running because if one of the points is closed , then it will be sucking voltage thru the coil for no good reason, and possibly shortening the lifespans of both the points, the ballast and the coil.

This is why I like the Accell Big yellow square top coil, because it has a huge oil reservoir, and a non-metallic case. Mine was new in year 2000 and is still going strong. I mounted mine horizontally on the apron and studs down. It has taken everything I dish out to it, all the way to 7000 and beyond. If you get one, also get the matching ballast.