I do not believe their is more than one TRW/Thompson power steering pump (as far as bolt holes goes). I think the aftermarket bracket is crap. It the Hoffman Winners Circle unit that everyone sells. I purchased a used oem one on ebay. We'll see if it fits when it arrives.
I found that you can rotate housing and there are two mounting tapped holes. One for small block and one for big block. You may just need to rotate to get your bracket to fit. It sounds odd but worked on the pump I just got (Federal)
Bryan
