If you are looking for ways to increase your grip strength here are two tips:
1. Dead hangs between sets of squat
2. Hold the bar at the deadlift top position for 3-5 seconds during warm-ups, or hold for longer on your rest days, while using hook grip or straps to keep increasing your deadlift PR.
This is just me, but I would never, ever let grip strength get in the way of my deadlift progression. I already got some straps before I started SS for when my grip starts to slip and in case nothing else works. If you can get your hands on a pair I'd suggest doing that until you can get what you have to do with your grip sorted out, or just use the straps on your work sets from now on.
Another option is to start incorporating long holds (hold 30 seconds.. 3 sets at ~1/2 of final DL set weight) and then eventually work up to heavy holds (last rep of working sets, hold 5 seconds):
YouTube
This works very well. I always used to hold the bar on the last rep for as long as possible. That's how I went past 315 on working sets with a double overhand grip and no chalk on my LP. These holds made my grip stronger and I have never failed a deadlift because of lacking grip strength.