This made me happy that I had made the swap :-)
You did a great job brother! Great job on doing it without too much $$$ too.
Lots of good advice on this thread. Advice that folks should follow. I didn't, just out of cave man dumbness.
A SUA YJ is a pretty forgiving suspension setup. I screwed up my pinion angle double, two different ways. I welded the perches on at the angle you should use for CV/SYE, but I still run the slip yoke. I also forgot to take off the degree shims, so my perches were set for that. Then I broke a leaf spring pin on the trail and lost a degree shim, so I drove it home from Tennessee to Ohio with one side shimmed and one side not. Once I got home I pulled the other shim, so now my pinion is at a random angle that is way too low. The driveshaft is fine.
A SUA YJ just doesn't have that much suspension travel, so as long as things are somewhat in the ballpark at ride height, it might not matter. Also when the springs try to wrap, the pinion points higher, so mine might be at the perfect angle when it counts LOL
As for the spring perch length, the advice on your thread is also good advice. However, in practice I think that the springs will get flattened anyway. I ran SUA with the Dana 35 perches, and when you hit the trails a lot, the springs try to wrap, and get flattened out. I am running SOA perches SUA now on my Dana 44, and switched springs. They are exactly as flat as the Dana 35 ones were. I think it is the nature of the YJ springs, they are flexy which is cool, but when you pound on them month after month they will try to wrap, and flatten out.
My point is, by all means do things the right way. If it isn't perfect, the SUA leaf spring setup is probably okay anyway.
I am starting to look into running Waggy springs on the rear of my rig, I need a little height, and a stronger leaf pack.
Great work, now go enjoy your Jeep! 2.5L of fury is the way to go