I don't know Bo. Personally I don't think it is worth the time and effort. I'm getting geared up do a friend's '98 Bonneville (L36 SII 3800) and we decided not to use the Ken-Co LIM repair kit or do anything homemade like in the thread mentioned. $80 and only a few suppliers sell it. The kits look tedious and in the end do you really save money and do the job right the first time? Plus supposedly it will not fit a Dorman UIM?
We are going with the Dorman UIM kit which has all gaskets and the revised GM lower intake manifold (LIM) which we got off a salvaged 2001 SII 3800 for $65.00.
Since GM came out with the revised aluminum LIM gaskets we're going to give that a try. GM part number 89017816.
The improved GM LIM part number is 24508923 just for reference.
IMO this is a better approach and remedy and in the end may be more cost effective. Another option is the revised GM UIM part number 89017272 and the revised GM UIM gasket part number 89017554 if you decide to stay GM.
Just my two cents worth.
