I did not notice the axle moving forward on mine when I did the ORD 4” flip in either a static or dynamic state. That must be a 67-72 issue as I have read many of you complaining about it. My old 72 Blazer had a small lift block in the rear to make up some inches for weak rear springs (and a 40 gallon fuel tank) and that thing looked like the axle was too far forward. I am an anal retentive picky SOB about details and appearance too and that would have bothered me if I had that issue with my 78. Zoomad can vouch for that. Heck, I spend an afternoon removing one single spring from each side on the rear packs because the rear sat 1.5” too high after the 4" ORD flip kit.
On my 78, while doing the ORD flip I also added 6” front lift Superlift springs to replace the 4” Rough Country springs. The combination of the 6” Superlift springs, front ORD HD shackles and rear ORD flip the trucks rides better than my dad’s Cadillac Fleetwood. No joking either. It rides nice. Definitely, better than my stock 2001 Silverado HD with IFS (I hate IFS). Let the air pressure down to 12 psi with a bed full of gear on the trail and you really get a nice ride.
The messed up thing is I never had any tire to fender interference with the 4” lift but often hear a rub now with the 6” when hardly twisting or hitting obstacles.
Guess these new 6” softy boingers flex a heck of a lot more or something hence the nicer ride.