In May of this year, at Jim's recommendation, I did the Rest Pause Challenge that incorporates some of the DoggCrapp Training methods into 5/3/1. Google that challenge, it's a T-Nation article Jim wrote in 2013. It's the four main lifts plus some rows, chins, curls and tricep work. That's it. I had to modify the deadlift day due to a back injury, so that day was always 3x3 regardless of the week, plus whatever low back/hamstring assistance work I could get away with as my "widowmaker" set. Usually this was rack pulls from the knee for a heavy set of 10, or 3-5 sets of GHR and reverse hypers. This worked for me, but I would rather have stayed with the original program. I had to "train what was trainable" as Jim says.
These days I train 3 days a week, combining the pull/press on Friday. I have picked a FSL protocol for each lift that I feel suits my needs best. I do my main sets, push the last set hard, do some FSL work, rows, chins, abs, and low back work. That's all, no other assistance work.
NOTE: I have found that when lifting each rep with as much speed as you have available and stopping the set when the bar speed drops significantly has given me plenty of volume within each lift to grow and get stronger. I do that for every lift. With submax training, you must push each rep with as much speed as you can muster, while lowering the bar with some semblance of control. Without that effort, you won't truly reap the benefits of 5/3/1. I know because I got it wrong initially!
I can't tell you my max increases derived from the Rest/Pause Challenge because I never max out. I did hit massive rep records on all lifts though, other than the deadlift because I had to modify it. It showed me the effectiveness of the 4 main lifts because that almost all you do. My future training will benefit from doing that challenge.
Lastly, if you do it, eat big! The program is only 2 days a week, but it will crush you if you don't eat enough. Also, I recommend doing 6 weeks and moving on. I did 12 weeks, and it beat the hell out of me.
I don't want to jack Joe's thread here, but there are some ideas for him if he wants to get back to basics.