1990 Sierra Uncomfortable/painful to clutch

Does anyone else have this problem? I just bought a 1990 GMC Sierra with a 5 speed manual tranny. I love the truck but it is extremely uncomfortable to clutch. The problem is the distance my leg has to stretch to clutch it. When I set the seat to a comfortable position everything feels great till I have to clutch it. I have to stretch my leg so far that it is very uncomfortable and after a little while actually becomes painful. If I scoot the seat up enough to not be stretching so bad I am sitting on top of the steering wheel. The truck has a bench seat.
I am 5' 10 inches tall so I am not extremely short or anything. Any input would be greatly appreciated. I love the truck but to be honest am getting to where I don't even want to drive it because of this. This is why I posted questions about how to convert it to automatic.