Thats a great idea.

I was lucky, I had my 302 torn down to a block with a crank, damper, front cover, and thats about it. I needed the damper bolt and washer for my new motor and I was lucky that I got mine off w/ the impact wrench. It wouldn't come off in just straight reverse, so I like to play with it going forward and backward and it'll usually loosen it up and come off. Always try to use the shortest length socket/extension possible when using an impact gun. An extension or unnecessary deep socket robs torque and some of the "hammering".