Yea, I did mine also - although at about 30K

But when I called 4wheel parts (the local shop) - they said that the 5100 was for "lifted trucks" - they swore that the 4600 was the same shock - I questioned that - but they said they would sell me the 5100 but the 4600 was the actual replacement & I would be happy.. I went with the 4600 but only time will tell... right now they are real nice...A lot better than the Ranchos...