Somewhere along the way my car acquired a 66 rear end. These rears have bolt in springs. The existing springs were the 66 style and were way tired. I ordered cargo springs (Moog CC501) as many here have recommended them and the pig tails look the same. When they arrived I checked the plate that holds the pig tail to the rear and it is a very close match to the cargo spring ends so I installed the new springs. Height is 2 inches higher (we'll see if they settle) which is good. I added KYB shocks, new insulators (Moog K6203) as well. The car drives great - very tight and smooth. Wow - what a difference! So if you find yourself with an early rear in a late model and need springs - the cargo springs are a nice option! I would post pictures but my wonderful pocket camera of 20 years died - bummer