My red light comment was referring to the PowerGen or Gener-nator and possible overheating issues.
However, I do know what the "old guy" was explaining to you.
When you ordered a new truck, you could select from the RPO (Regular Production Options) to purchase different ampacity generators. My engine came from a 6400 fire truck tanker that has a 55 amp generator. Still working well today. No problems running a 6 volt system.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
