Not's not 100% correct Jim.
The UIM in it's entirety gets the Extrude Hone process. Not one side vs the other
The 98 & 98.5 SVT's get the process done once.
The 99 & 00 SVT's get it done another time (dual honed)
The 99 & 00 SVT do have both the primary & secondary head ports EH'd while the 98 & 98.5 only have the secondary head ports EH'd.
The LIM never gets the EH process.
There is the stock LIM, the 98, 98.5, & early 99 LIM (+2mm bored stock) and the late 99 & 00 LIM (3L lower +2mm more/+4mm over stock)
On the Dyno; the DH UIM vs a SH UIM made around 3FWHP/TQ through the entire powerband on a moderately modded SVT.