Running small envelopes on Presstek 52 DI

[Prime12]

Hi
This is my first time with this forum and was hoping someone could give some advise. I'm trying to run #10 envelopes on a 52 DI. The book says my minimum size for with is 4.33" and #10 is 4.125". I've managed to get the feed head to pick up and deliver straight onto feed table but when it hits the headstops it twists a little bit. Depending on the image you can not notice sometimes. However I would like to have it more consistent. Also I have been asked to try to get #9 envelopes to run. I can not even get it to feed onto table straight due to the suckers having not much stock to grab. Any hints or feedback would be appreciated.
Thanks