Hello Scott ... congratulations on your 14x17. I shoot 8 x 20 and had a similar problem when developing in a large drum on a motorized base with Pyrocat-HD. After some experimentation, I ditched the motorized base and got a manual roller base (drum rolled by hand) and slowed the rotation to about 15-20 revolutions per minute. I also use a forward/reverse and side-to-side agitation that is very effective at keeping the developer moving in all directions to avoid getting streaks. This is easier done at slow manual rotation and produces very even processing. So, as an example for the first 60 seconds of processing, I roll the drum 7-10 rotations forward and side-to-side for 30 seconds, then reverse direction and side-to-side for the next 30 seconds. This is repeated for the balance of each minute of processing time. With the expense of TMY film, it is a pleasure to pull an evenly processed negative from the drum.