My rear brake line crosses over to the passenger side and tee's on the back of the rear axle making the left rear the furthest away by the way the line is run.
I bleed in this order LR, RR, RF then LF. Check the way your lines are run to be correct on your truck.
Also, don't forget to replace the steel lines if they are original. They might LOOK good but after 50+ years they can rust from the inside out. They ars not very expensive and can be run in less than one days work. If you have a bender you're in good shape, if not they can be bent CAREFULLY around a round pipe (about 3 in. diameter). DO NOT KINK.
The rubber lines can colaps on the inside and act like a check valve not allowing the brakes to release, so replace them too!
Be Safe!
