Getting ready to order a 200 amp alternator and I noticed that on autozone's website they have different part numbers listed for the 5.0's and the 2.3's for the same alternator 7745 for the 5.0 and 7745-10 for the 2.3. 6645 for the 5.0 and 6648 for the same one for the 2.3, etc. Just want to make sure before I order