Boot camp is made to make you hate life. 12 lbs lucky bastard, I went from 212 to 178 inn boot. I'm at 220 now and plan on going up (6'5") muscle won't hurt you, makes it easier to carry your whole load IMO. Your no where near max weight I'd assume for your height, then your fine to go up.
anything and everything that will help you move uphill with weight. whats your MOS if 0311 doesn't matter their is a mental game and running but a weapon MOS is carrying weight, and lots of it.. Kettle bell swings, deadlifts. IMO the exercise that uses the same muscles as going uphill (I have dozens of threads asking USMC questions) sumo deadlift high pulls. Do those and burpees. Fartlek runs inbetween lifting days and you'll be good.
I'll say it again, sumo deadlift high pulls
burpees
fartlek running
P.S. you'll notice people sneak food into SOI all the time, IMO wait a week to see what happenns when people get caught they might legitimately get in trouble if not do it. Don't be the dumass eating a butterfinger. Protein bars and pop tarts every night allowed me to gain weight while there. (no joke 2 protein bars and 1 pack of pop tarts every night worked great didn't start till week 5 I regret not starting earlier)
P.S. keep working on pull ups they really will decide if your fit on not by that first PFT.... you don't wannt to be labeled out of shape, so absolutely do some running as I said.