The only way I know of to permanently join two pieces of metal is to weld them together....and even that can be taken apart with a cut off wheel. But what I would really like to know is how you weld aluminum to steel, that is one trick I really need to learn. And if you really knew your cars like you are trying to pass yourself off as knowing, you would know that aluminum plate with "Hurst" cast into is just a mounting plate bolted to the trans tailshaft like damraider stated in his post. And the only 340 that came from the factory with a Holley was the 340 6pk, they had three of them in case you didn't know what that was.