May just need a good cleaning then syncing at most! Any reason you'd want to mess with jets? My Honda manual says the K3 had 105 mains, 40 slows, air screw at 1 +/- 3/8 turns and float height 26mm. No mention of needle position but do any come with something other than the middle position?! Maybe install a K & N air filter to get more airflow/less restriction to counter altitude's thinner air. Playing with carbs for no reason is like playing with fire. I'd set them to stock as the starting point, sync them then do plug chops/reads and adjust jet sizes/settings based on what you see and how it feels. My gut tells me at the most 1 size smaller main but you already have 105's so I'd bet it won't be necessary.
As Gordo says, get in touch with Hondaman. He does carbs too.
