The idler pulley assembly had the wrong thread count. It wasn't noticeable until you tried to tighten it down and the threads are just small enough to make their way in and strip the female threads off the mounting hole on the side if the block. Wouldn't tighten down and once I discovered the problem it had done enough damage to the threads on the block that the old idler pulley bolt won't tighten down now either. More than likely ended up costing me an engine. The other parts fit tho.