***Update***
As I mentioned yesterday, I tried one o-ring which made my idle way too low, and two still kept it around 1200rpm for a few minutes. This morning I went and disconnected the battery and then started it. After a few starts, all is normal. Now, with one o-ring, it idles around 1000 rpm and settles down to 650 in short order. Looks like resetting the ECU's memory did the trick.
As I mentioned yesterday, I tried one o-ring which made my idle way too low, and two still kept it around 1200rpm for a few minutes. This morning I went and disconnected the battery and then started it. After a few starts, all is normal. Now, with one o-ring, it idles around 1000 rpm and settles down to 650 in short order. Looks like resetting the ECU's memory did the trick.