A " HEI" ignition system is an imaginary solution in search of a problem to solve!
Jerry
Points based distributors require more periodic maintenance than a solid state HEI based system. That is why I am making the change.
The tapered seat is my mistake. I didn't realize they changed the seat between the 283 and the later 350s. The GM spec plug is an AC44 which is not available anymore, so I went to a later model that I believed should be equivalent
I have not been able to find actual specs on the AC44 plug. Depending on whose cross-reference chart you look at it maps to resistor plugs, non-resistor plugs, 2-3 different lengths, and all the heat ranges that exist.
The R44 and R45S both show up on most of those lists. You recommend the R44 specifically?