I just looked under my Fleetside. The rear crossmember on it lines up with the spring perches and the crossmember and perches are riveted together. There’s only 19” between the crossmember behind the differential and rear crossmember.
Bummer, I sure like your installation.
Thanks for the info.
Dan
35 CC Case 38 Chevy Pickup 51 3100 AD 58 3100 Apache Fleetside