Last night, it occurred to me that my trucks runs MUCH better when it's cold... but, performance is noticeably reduced once up to temp...

The KSB advances the timing (among other things?) on the IP when the engine is cold, correct? And once the engine temp comes up, reverts the timing to normal?

Does this sound like a situation where a timing bump may benefit my rig? Also, does such a bump effect the engine idle speed?

 

Yes, yes, yes pending how you use your truck, and perhaps pending how far you push things. It's no big deal to adust.