It is a little bit hard to tell by the pictures, but to me it looks like you might not have taken the ridge out. If you didn't, it is quite possible you may have broken the rings and possibly the ring land. The crosshatch doesn't look quite right either, although again, it is a little hard to tell by pictures.
Those Chevy motors usually have quite a bit of taper and if you don't take the ridge out you can easily break the new rings. That is about the only thing I would think of by looking at the pictures.
If you didn't take the ridge out, I would suggest removing the pan and knocking the pistons out to see what is going on.
That is a nice old Chevy pickup, it will all be worth it when you get this straightened out.
