Couple minor YMMV things,
Inverting springs, actually reverse arch when flexed, is pretty common when wheeling SOA. Yes, it's tough on springs, but it's great to have the flex. It works for me.
When the axle flexes up the wheel rotates in as it goes up. This means you want to tip the top of your shock mount in toward the engine as much as possible so the tire doesn't hit it. My shock hoops are tipped in a enough to require cutting a small 6x6-inch hole in the inner fender. It allows a longer shock and it tips in a bit.
I've never had a anti-wrap bar. And never broke a pinion. I think heavy OME springs, good perches and most of all good pinion angle (nudged a bit low in back and high in front) are fine. The "nudging" means the pinon "comes into line" under load, rather than being perfect static, then going out of line under load. Just a little nudge.
On the backing plates, I just got tired of messing with them one day and drilled out the rivet that hold the brake line to the cover. I replaced it with a "thin" nut tack welded to the cover. No more need to break the brake lines open for the birf job.
