Well since I opened my mouth I owe some more pictures and a diagram. The template isn't as good as I thought so here goes. All of the pieces were made out of scrap so some aren't too pretty.
I first made a pattern out of a manila folder, cutting and wacking til it looked like it might fit. I then cut a 1/4x7x6 1/2" plate and cut it to look like the pattern in the enclosed file. All sides of the 7 x 6 1/2 plate started out parallel to each other. I then took a 2 1/2" x 7" x 7/16 flat bar like shown below and drilled 2 holes to match up to the head. I think the critical measurement is the 3 1/4" outside front to back that spaces the pump correctly for the belt. The idler bracket is just a 2x15x7/16 flat bar mounted with the pulley.
I feel the 2 bolts holding the bracket to the block are sufficient. So bolt the 2 1/2 flatbar to the head, then cut a 2 1/2 x 6 1/2 x 1/4 strip to weld perpendicular to the plate bolted to the head, setting it about 1/4" in. Bolt your pump to the plate, hold it up to your tacked perpendicular piece and if it fits, tack it together. Then cut two small pieces to fit on top and bottom to box the assembly together. You should now be able to unbolt the pump with the bracket still attached to the head. If all looks right, weld that sucker up.
The remaining two holes are for the idler pulley. I had to grind some relief holes for the ratchet extension which is shown in the drawing. So bolt the assembly to the head, bolt the pump in, I had to use a few washers for the bottom hole between the pump and bracket, then bolt the idler arm on.
I forgot to grab the belt I used before I came in so I'll post that later. Whether the size works for you will depend on where you place the idler pulley, mine is 7 1/2" from the top hole in the flatbar. There was lots of trial and error doing this, but with a torch, grinder and determination it can be done.
I had to take my pump off today to get the measurements for the bracket, but I've learned so much here I'm just trying to pay back. I know a guy who might be able to make these, I'll try to see him tomorrow. This bracket isn't fancy, but very functional and since is steel, if you have a welder you can make it.