How do you train to max pushups on an APFT?

I went from 55-60 average to hitting 80+ from doing dips. The whole muscle memory and just doing push-ups to improve never worked for me. Started out doing dips, then weighted dips and I saw a huge improvement between my pt tests

Keep pushing

'Do push ups with your kit on daily at home whenever you come inside then when you do the soft without your kit it will be easier to max

I had the same issues. I'm 6'4" as well. IF I could get 90 points on the PU, I'd easily max the other 2 events. If I couldn't, well then I'd just take it easy and aim for 80 points in the SU and run..

Nothing you can do replicates push-ups. Practice. Practice. Practice.

Do as many Correct Push ups as you can, To muscle Failure,
Then go up to 45 Degree angle and continue until you experience Muscle Failure and then to 60 degrees and repeat.
Do This twice a Day about 10 to 12 hours apart... for 5-6 Days a week ... Your body needs at least a 36 to 48 hours per week to recover and heal the over Stressed Muscles...
you might want to add something like Muscle Milk or Whey Protein shakes twice a day to assist in the Building of Lean Muscles...

Funny coming from a PFC but I went from 45 push-ups to 80. Weight room Chest Monday and Thursday. In these workouts hit All three types of bench (incline, decline, regular) with a set of 120 using the bar or 5lbs on each side doing intervals of 20 of close grip, regular grip, wide grip until you hit 120. Then hit 3 x 3 with heavier weight 70-80% of your max. Then end the workout with a pyramid of 20 push-ups

work the arms, curls, push ups etc.

I do 75 pushups every night. Start with smaller sets to complete your nightly 75. Focus on form! If it does not count, don't count it! Once you reach 75 without stopping continue nightly sets to maintain, or work to a new goal! I am also 6'4 and 175 lbs.

First, strip the PT belt. The Army...that is awful.
I'd rip that thing off first and foremost.
What's next, Depends? You know, just in case.
What a disgrace (not you, the Army. C'mon, leadership. Really??)

As for your question, keep pushing. Your lankiness works against you (W=F*D, that is, Work = Force x Distance; since your palms and shoulders are farther from your elbows than shorter guys, you need to generate more Work). Do lots of push ups. Keep working.

And ditch the PT belt. It communicates weakness and makes you feel incapable.
Rip it off and then knock out the max.
Airborne!

100 push-ups every day for the two weeks prior to the test. Start with sets of 10 and work your way to sets of 40-50. Do this and I 100% guarantee success.