I am changing my 3.23 out for a 3.42..... what do I need to get to correct the speedo reading?(part numbers would be usefull) How far off will I be untill i remedy the problem? Also, how can I make sure that this ring gear and pinion are infact a 3.42 set? I have never been screwed on the classified board here as of yet, but i would like to be sure before the damn thing goes in.