I finally got the 3.4L in and running. I had all sorts of problems, mainly my own making. I did the 4.3L tbi conversion at the same time.
The motor is running but I'm not satisfied with it yet. It seems to be basically sound but it still idles too high, surges from 1000 to 1500 especially when cold and runs a little rough while accelerating. And I don't think I'm getting the power out of it that I should. I suspect the TPS or a vacuum leak. I had to replace the TPS and I've tried to adjust it but it didn't seem to make any difference. I searched for a vacuum leak (I even used the propane trick) but can't find one. I also set the timing to 10 degrees BTDC per the instructions for the 2.8L.
If anyone out there has any thoughts about what may be causing these problems I'd love to hear from you.
Jim