In some of the 8.8 threads they talk about the proportioning valve. Some said they removed the o-ring on the piston in the proportioning valve but no one said which o-ring so it must be the one in the middle. I am in the middle of the swap and still have to install the master and bleed the system. I took the metering rod out of mine and cleaned it up look at the o-ring but left it on.
Some other threads I read said to get a proportioning valve out of another model Jeep with disc brakes and no ABS. That would give you the metering for four disc brakes and no ABS will leave another connection on the body of the valve so you it would be a straight swap.
So I have a few decisions to make. But then a few more threads there was guys locking up 35s no problem with standard equipment in their YJ.
So I have no real answer for your issue just sharing some ideas for you.
I have a problem with the emergency brake cables that came in the kit for ECGS the passenger side is about 1" too long when you get it to the single pull on the drivers side. Let me know how you hooked your up and where you got the cables. Thanks.
89 2.5 TBI, 4" RC lift, 1" Booms, SYE, Adams Driveshafts front and rear, Ford 8.8 with 4:88s, BFG 33X12.50X15, and a ton of other stuff.
AF Jeep Club Tail Number 184