I am working on my 67' C-10 It had, what I believe was a dealer installed power steering unit. With hoses going to a cylinder in the steering linkage instead of the steering gear box. I converted to a ps gear box now, but I am questioning my brackets. They have it set up with a single belt runninig both the PS pump and the alternator. The PS pump is mounted solid with no adjustment and the alt. is in the original location with belt tention adjustment slot. There is only one grove in the water pump pulley and the ps. pump pulley. The only thing I question is the amount of belt contact with the alt. pulley. Only about 1/4 or less of the pulley is in contact with the belt. Is that enough?? When ps pump is not installed belt contact is a little less than 1/2. Does anyone have pictures of what it is supposed to look like? Or should there be two belts?

Do a search and you may find something like this.
The last post has a link to pictures I posted on another forum.

http://www.inliners.org/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=003140#000007

The power-assisted steering was OEM for '67 and prior. The powered steering gearbox didn't come out til '68. [If I'm not wrong.] I tried using a '69 steering gear on my '67 K/10 Suburban and had a lot of problems. I guess on the C/10s it's not so critical, but my steering geometry was all screwed up -- it took 3 lanes to make a 180*. When 1/2" grade 8 bolts were shearing off, I got concerned.