Why are your rack pulls so much lower than your deads?
That's a good question...
There are two possible answers (or maybe the answer is some combination of the two);
1) It's only my second time doing rack pulls, I'm still getting a feel for it. With the speed these were going up, I could probably do a bit more weight, but I'm not quite comfortable with it yet. In particular, the first rep of every set felt really hard, but subsequent reps were really easy. I get the feeling I'm not setting up correctly for that first rep.
2) I've got the pins set on their lowest setting, which is right about where my sticking point is (I would like to set it a bit below that per your advice, but like I said, lowest setting). I pull real strong off the floor, and if I'm going to fail it's going to be right as the bar breaks the knees. If I can get it past my knees I can usually lock it out, although I can tell that increased lockout strength would still help. Right now I'm strong on deficit deads because of my strength from the floor (last time I did snatch-grip deads off a 3" platform, 315x5 was easy, only limited by grip) but my weakness is from the knees up, which is why the rack pulls aren't as strong as they should/could be.
Secret answer 3) I recently brokered a deal with the devil for improved deadlift strength, but the deal did not include rack pulls or other DL variations. Stupid fine print.
Side question: What grip do you guys like to use for snatch grip deads? Alternate grip feels kinda strange that wide, and my thumbs feel like they're going to fall off if I use hook grip for reps...should I just use straps?