Sorry, I couldn't find a metric ruler, so I had to print one out, but you get the idea.
I have a UIM from a 00 and a UIM from a 98.
00:
98:
00:
98:
I have carefully measured (and remeasured) every single opening of both the 98 and 00 UIMs and found no difference in the ports openings, throttle body, IAC, etc.
Visually, no difference other than the part# and the following pic from the 00:
This "groove" is in the smaller ports of the 00. The 98 does not have them.
Hope these pics help.
