Without...
the vert steering, you can run the Cat 8.5" riser. Thats as high as you can go without an extension. I was going to just find a 4.5 or 5" riser and go without an extension, but I liked how they felt where they were.
I noticed you don't have vertical steering. With it 4 inch is is the biggest block you can run. I have a 5.5 an a 6 from before I put vertical steering on and once I did I tried them and there is no way to get enough cable to make it work with out extensions.
the vert steering, you can run the Cat 8.5" riser. Thats as high as you can go without an extension. I was going to just find a 4.5 or 5" riser and go without an extension, but I liked how they felt where they were.