Ron,
If a "rag joint" was used to connect your Impala steering column to the Pacer steering (not sure what you have as I don't think I have ever seen a picture of your actual front suspension/steering details), that could be a possible source of the truck wandering down the road.
I would 2nd Kevin's suggestion to have the front suspension thoroughly checked for wear and alignment, especially if it hasn't been gone through since you had it built/installed.
Of course, there might be a little wandering eye or wandering mind going on as you tool about your locale.
Just saying my friend - haha!
A steering stabilizer isn't going to help you out, at least at this point. A chauffeur with a stead driving hand may though.
Dan
