My first Sherman Easy Eight has a similar setup and I seem to recall using a Pershing bracket and Recoil (recoil unit is the same as Super Sherman) and keeping the assembly closer to the mantlet solves the problem. I will add that I am using an older Back Yard Armor turret but I also have a Nick turret on the shelf that works. You can remove some of the stay if needed.
http://www.desertarmor.com/DAK_PROJE...na_Boy.html#33