Timing request 100 shot 360

Everything I have seen or read says that the original "safe" jetting on the early kits were horribly fat. Monty Smith told of a test he did with an adjustable jet plate setup, where he started with the factory recommended jetting, which he then leaned out the fuel jet three times, picking up power each time. His final jetting tune gained 100hp without touching the nitrous jet. Or hurting the motor.
Reading the same type of posts on how fat the factory jets were is suprising.
Why have they not reposted leaner tunes?
Is there possibly a safe factor built into the old fat tubes helping keep you out of the lean territory in the event something went wrong?
Looking forward to p/u an a/f ratio assy. I'm interested in that w or w/o spray as it's just sounds like a gr8 idea.
Totally still learning here. Lots of studying