Jay,
That bracket you have is for a radial compressor, I have the exact one on my 82 c-10. In your pictures you have a diagram of an old 6 cyl compressor( that is the size of the compressor, not engine). That was used in the 60's, early 70's, till gm came up with the radial compressor to work with the large dist (HEI). I have an old 230 block in the garage, will look tomorrow and see if the front has a different boss on the block for that lower mount. I'm sure someone must make a bracket to put a/c on a straight six.
