Spool or Locker?

brian6pac said

Power lok is the best of both worlds, rebuild parts available, easy to find in old trucks. The more power you put to it the harder it locks.

Click to expand...

Ok, so when when the 35 spline axel came in the´70 Dana 60, the Power Lok was still in it. Than change to the less desirable Track-Lock in ´71? Or am I mixing thing up here...