Roger, somewhere along in that era, they started using bubble flares instead of 45 double-inverted flares. The bubble flares require a little different setup unless you get a tool that does both. I ran into this drama when installing the '92 8.8 disc brake rear under my truck. I saw a youtube video showing how to make bubble flares with a standard tool but I had no luck with that. I ended up buy a few lines with bubble flares then cutting them to length and doing a regular flare on the other end when mating the older stuff to the newer stuff.
I also have a Rigid flaring tool with standard U.S. sizes. It doesn't hold the metric lines very well at all. I don't know if your truck has metric or standard but you'll probably want to sort that out before purchasing.