There will be plenty that can help. Post in the Hipo forum. Some of the gmc guys like myself hate seeing gmc trucks get turned into chevy trucks by individuals believing there is only one path to achieve a highway capable vehicle.
In the end, it is your truck and you can do whatever you want to it and with it.
I have had 3 59 gmc trucks, so I am pretty attached to the model and year. My first had the 270 and a 3 on the tree and would go all day long at 70 plus on the freeway. It pulled high elevation passes as well in the snow with chains hundreds of miles from home.
One of the coolest parts of the 59 is the foot stomp starter. You will lose that as well as much of the feel, smell, sound, and charm of the 50 plus year old vehicle.
