Regarding CAPS: put the contents of the zip file in a directory called WINCAPS directly on the root of your C: drive (i.e., C:\WINCAPS) then run CAPS.EXE to launch it.

As Don mentioned, you'll need your cat for both passing smog and for proper back-pressure. If your cat is the original (not sure how you'd know other than if it seems to look like it's not 21 years old) it may need changing. I put in a new cat in mine a couple years ago and performance was noticeably improved. I picked one up, along with the attaching hardware, from Advance Auto. Again, as Don mentioned, however, you won't know if you'll need one until you've had a smog check done. IIRC, high HC and/or CO emissions could be attributed to the cat, so if you fail from either of those your cat may be suspect. Just be sure that before you take it in for testing, that you drive it around for about a half-hour beforehand to get the cat good and hot.

As for the O2 sensor, better to check it to see if you're getting the proper readings from it than to just change it. It's seemingly not a difficult job to change it, but if you're unlucky enough to have one of them that has welded itself to the exhaust manifold (like this one) then you could be in for more than you bargained for. Easier to check if you even need to change it in the first place.

That mild hesitation under load you mentioned could be the depression chamber, the cat, or possibly just and old carb needing to be rebuilt. Not sure if someone's mentioned it yet...use NGK plugs. DON'T go get those Bosch 4-points that have suckered some people in (including me). The Bosch's are not good plugs for this engine.

Let me know if you've got a timing light and if your multimeter will register engine RPMs. If not, I'll bring mine my TL and meter. If your timing's not set correctly for the altitude, you'll see a difference. Basic timing is about 7? BTDC, but at this altitude it needs to be about 11? BTDC (IIRC).

To each their own, but I've always just ran 10W30 in mine year-round. I've been using Mobil One.

Don, I know that junkyard on Radcliffe (Colorado Auto Parts http://www.coloradoautoandparts.com). Been there a number of times. It's a big yard, so the odds of finding what you need are fairly good. There are also a couple of Federal, Zuni, and a Pull-N-Save in Aurora, near where I-70 and I-225 meet (http://www.pullnsave.com).

And thanks for the props, Don, but I'm still cutting my teeth on maintaining this engine. I'm more of a suspension and drive-train guy. I'll help as I can, though. <img src="/forums/images/graemlins/smile.gif" alt="" />

And, Phil...good to see you drop back over here from the oil-burner's club. You need to poke your head in more often and say hi!