Problems with 2001 WJ steering pump on XJ

I know people have done the 2001 WJ steering pump on an XJ before but I am fighting this. I took the WJ pressure side hose and brazed the larger tube down to the size to fit the XJ steering gear. My problem is that even though I have gone with the larger 1/2" return line, the pressure in the return line is too high and it keeps ruptureing. I have tried three different pumps/reservoirs with exactly the same luck.

It happens immediately at an idle.

I am running a ported box with ram and a PSC smaller diameter pulley, but since it ruptures before I even get it out of the garage, I can't see that the pulley is related.

Anybody ever seen this problem?

Did you use the larger fitting on the WJ pump or did you move the XJ fitting to the WJ pump?

I am running a WJ pump on my XJ. When I installed mine I put the XJ fitting onto the WJ pump. Its been on there for more than a year with no problems as a trail rig and DD for a little while.