I have noticed that my 94 GC pulls a little to the right. The person I bought it from said he just did some steering and suspension work on it, so I hope it is just a slight mal-adjustment. When I am driving the freeway, it is less noticeable. But during slower speeds, and regular roads, I can sense the inclination to move that way. I have to keep a very mild heavy hand on the left side of the wheel.
It is very slight pull to the right, nothing like what I dealt with when I had a 66 Mustang coupe, which seemed to want to go in circles (don't even get me started on braking that car). I've checked the pressure in the tires already; they seem fine. I crawled under the car to see what it might be and saw that the steering bar (?) looks like it might have been worked on fairly recently. I wonder if it is an adjustment here, as he did say he did some front end work to firm up the steering.
One more note: When driving straight, I can more easily turn the wheel 45 degrees to the right than I can 45 degrees to the left.
Are you just fighting the crown of the road? (you know, the slope to keep water from standing) Try driving down the other side of the road and see if it goes away. (of course, do it only when you can see that there is no other traffic - especially cops)
I've also heard (but not sure if I believe it) that cars are designed to pull to the right in case the driver falls asleep, having the car end up in the ditch instead of oncoming traffic.
Another thing to consider is the alignment. If he just worked on the car himself, it may not be properly aligned. For ~$75-100 bucks, it's worth it to get an alignment.
The second thing about an alignment to consider is if it was aligned to compensate for the weight of the driver. Some shops will adjust the alignment so it drops even when the driver gets in. If the previous owner is a fair amount heavier than you, that could be the problem.