The Stovebolt Site Forums The Shop Area Engine Shop Mallory, Pertronix, Langdon or??

Hey Deve, There is a reason that the "modern" HEIs look so different. GM made them fatter so there was less chance of crossfiring in the cap. Also, to get HEIs to work right, you have to replace the vacuum advance with one with a lower opening "pull," and replace the counterweight springs with lighter ones. The reason for all this is to get around the fact that the HEI was designed for emission control, and NOT High Performance. That HP was part of the package was a freebee that all the boy racers took advantage of. Like the 235, the 250 and the 350, the HEI is a good idea that folks will continue to use and modify for years!

Best wishes,

Les