When it came to accessory brackets(alternator and PS pump only) I once again found myself consumed by a combination of fewer options than I expected, and not being happy with what was available. My LS engine runs the Cadillac CTS-V balancer which is extremely short and close to the block(a very good thing). Unfortunately it REALLY limits the factory and aftermarket options for accessory drive brackets since most LS engines are in Camaro's, Corvettes, and truck/SUVs with a different balancer alignment.
My biggest challenges were 1) finding brackets for only Alt, PS, and tensioner, 2) all with the correct back-spacing, 3) keeping things tucked in nicely with the block and not hanging way out(aesthetics...), and 4) having the right "look" for the car(all personal opinion). While taking sanity breaks from making my custom headers, I decided to just make my own brackets. My plan was to mill them from 6061 aluminum so I first grabbed dimensions of the bolt holes from the block. I made some extremely crude center-marking pins from bolts I cut up, threaded them into the correct holes, held a thin plate up to the bolts, and tapped on the plate with a hammer. This left a small indentation which gave me the exact location of each bracket's holes.
I then measured my pin marks and plotted them in Fusion 360(CAD software). I grabbed the dimensions from the alternator and GM type-II PS pump and got those bolt holes as well. I sketched out some ideas, then created 3D models for transferring to a CAM software for the CNC.
Short term I can't get to my buddies shop to mill them so I took 2D drawings and traced them on 1/4" steel plate. A few hours with an angle grinder and disc sander and I had my brackets in steel.
I have the Eastwood powder coating setup which has been extremely handy over the years for these kinds of projects. 25 minutes baking at 425* and my brackets are done! I cut some thick-walled aluminum tubing for the proper spacers and think I have the belt completely aligned to about .010" which is well within spec. I can now get things installed to check for belt length and move closer to getting this engine started for the first time!
Just like making the headers, this really wasn't difficult, only time consuming. I have $10 in plate steel and probably $12 in angle grinder disks. The rest of the tools were all extremely basic to make these in steel. The CAD/CAM software was only needed for milling them in aluminum later, and 100% not necessary for this first prototype.
In the end, if you can't find what you want, MAKE THEM! I've seen some really creative brackets with rod ends and other nice adjustment features. It all comes down to creativity. Anyone else with a similar set of homemade brackets?
-TJ