The wheel back spacing or the spring perch location doesn't have anything to do with the axle or housing length. Is the housing stock or has it been shortened? You need to measure what it is and compare against what a stock housing is. Maybe you just got the wrong axles.

"Follow me the wise man said, but he walked behind"


'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion.
'74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion.
2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.