Combine - What weights to use on lifting portion?

What I lift: *SETS* -edit
Squat - 4 reps 275, 4 reps 315, 3 reps 385, 2 reps 405(failed on 3rd)
Bench - 4 reps 205, 4 reps 225, 3 reps 245, 3 reps 265(+3 reps little help)
Power Clean - 5 reps 155, 3 reps 165, 3 reps 175, 2 reps 185, 2 reps 195

At this free "combine" that a local college is hosting for high school students I have a question about what weights to use for the weightlifting portion of the fitness test. You get to choose your weight (says "# of reps at comfortable weight"), and I do know that they just record the weight and reps you did at that weight. The previous years they have not put your reps and weight into a calculator to get your max, but if they do should what weight I choose to lift change? What would be a "comfortable" weight for me to be lifting?

Also if someone could do calculations on what my 1 rep max would be for these lifts that'd be interesting,

Thanks!

look up bench calculators on google, there are a ton out there. Put in different weights and reps that you can do/have done. Pick out the highest weight the calculator gives you. There shouldn't be a huge difference but some people are better with low reps heavy weight, and some people are better at higher reps. Do what you can do best.

Had the combine this morning did really well I think in the weight room today

squat 385 for 7 reps
bench 275 for 3 reps (I dont think i warmed up enough, thought I could get more..)
power clean 205 for 6 reps