I bumped up from 3" to 4" springs. Got a very high frequency vibration around 30-35 mph. Kinda knew that was coming so i had a xfer drop kit on standby. Installed the drop kit and there was no change for better or worse.
Before the drop installation the rear drive shaft looked pretty darn straight as the rear springs had built in wedges.
Now naturally the shifters and clutch rod are lower and hard to shift and clutch rod is rubbing the fire wall.
PS. The built in rear spring wedges have fat end facing front. I reused my 4* wedges up front with fat end facing front too.
Torque is the measure that gets the cap off your beer.