90 degree adapter leak

It is a 69 340 block and the adaptor was aluminum style with a steel bolt. The holes on the bolt were two low and two higher I think. When I changed to the original plate I used a factory plate steel and the threaded bolt. I now used the Canton plate with the factory threaded bolt and O ring as they recomend. I have MP gaskets coming today and gonna try again. Just looking for any advise to avoid another failure. Again I scraped and scuffed the block prior to assembly as well. Is there a recomended torque spec on that bolt?