Here's one heck of an update. Not exactly done with this project yet, but the mock-up picture was too good not to share.
Problem: No alternator on my LSx motor.
Have: Alternator from my BBC and the bracket that went with it.
Solution: Adapt my junk to run with the truck pulley, waterpump and tensioner.
Here's a reference picture of the head
Basic location and spacing I had in mind.
After making some measurements (including the difference in the depth of my alternator and the waterpump pulley), I found I needed a 1-1/4" plate and I would have to pick-up a hole on the cylinder head with the spacer plate.
Got this big hunk-o-aluminum from Midwest Steel Supply. It's 1-1/4" thick, 6"x8" T6 aluminum and with shipping was surprisingly cheap. I could have ordered a smaller size, but I wanted extra just in case.
Sorry if these pictures are excessive, but I like them. I layed out the pattern using my existing bracket, made some reference marks for the holes (do not drill these) and marked the inside area where I want the other cylinder head hole to end up.
I managed to find a bandsaw somewhere and cut out the plate. You can hacksaw or jigsaw this, but I wouldn't recommend it.
After clamping up the BBC bracket to the spacer plate to use as a drill guide...
...I used a 'gunbarrel' drill bit and backdrilled the holes.
After measuring out and drilling the third hole, I mocked the spacer and bracket up to the head.
