Re: EL XR Series 1 vs Series 2
series 2's were standard with the 16" rims. October 1997 change date. The diff tag will have 3:45:1 on it not 3:23:1 of the EL series 1. Explorer inlet manifold - squared shape the HO was a rounder shape. Different factory headers, ELGT styled, will be fatter and of a glossed grey color. and i think the twin tips bit is right as well.
However the diff tag or inlet manifold would be the most reliable ways.