With that HP & RPM you'll need more upgrades.
Are you using the Hi-Rev 3-4 release springs?
May want to upgrade the Output Shaft aswell, 4L65E, Cryoed or Billet shaft.
You should talk with Dana about your goals/plans, parts you're thinking of using and see what He thinks will be needed. He specializes in the 700R4/4L60,60E,65E,70E.
These have detailed kit Info: 87-93 models; 82-86 kits also available.
675HP >> https://www.700r4l60e.com/store/prod...&cat=19&page=1
750HP >> https://www.700r4l60e.com/store/prod...&cat=19&page=1
Yes, PATC has a very nice site for parts.
700R4 Parts List at PATC Raptor Transmissions
I hadn't seen the single sided Red Eagles before now. I've also noticed many Builders using the Hi-Energy clutches.
The solid Teflon seals are much better when running higher pressures & handle heat better.
Some Info >> 700R4 Parts List at PATC Raptor Transmissions
You can use pieces of Mylar, Plastic bottle etc.. & Hose clamps to shrink/resize the Solid Teflon seals instead of buying the fancy tools.
The Low/Reverse tool is worth buying or making. About $30 on Evilbay.