I've found it way harder to get a rear axle straight than a K member. Especially when using adjustable everything on the rear. My 85 took me many hours and a ton of measuring when I installed the Series 1 kit from Team Z. Mocking up, then measuring for the ARB. Welding tabs. Adjusting the uppers and lowers for centering and pinion angle. Then I painted the axle housing, then set it all up again to make sure nothing changed.

When I installed my aftermarket K-member it went into place and really didn't have any movement/adjustment at all. Dropped a plumb bob. took 4 measurements and it was all straight. I didn't need to do anything other then bolt it on and go.

I took my old SVO to a high end alignment specialist shop in Albuquerque. He started out checking that the rear axle was centered and aligned properly saying that if the rear axle is not correct, the car will never track straight down the road. My rear axle didn't require straightening but it was still verified. It was never wrecked and only had stock control arms with new bushings. This was after I swapped in an 8.8, all new Koni's as well as some MM camber caster plates. It was tough to argue with his results as the car was perfect when it left his shop.