Jim Wendler responded to a common 5/3/1 question.
What to do on week 4 – the deload week if you don’t want to completely deload?
Week 1 – 3×5 (as normal)
Week 2 – 3×3 (as normal)
Week 3 – 5/3/1 (as normal)
Week 4 – 65%x3, 75%x3, 85%x3 (don’t go for max reps)