I was just looking at the 440 source combo for my 4x4. Using the 24cc dish pistons were. 050" below deck. With milling the block deck that. 050", it would bump the compression from 9.5 to 10.3 with my 84cc heads. That's if you could get 4.350" pistons. All the pistons listed were. 055"+ os. Of course this is for a 4x4 and not a race engine, so I think it would be a good stump puller on pump gas. The girdle would probably be a good idea, even for what I'd be using it for. Just wasn't sure if I wanted to go that big, having to use external oil line. I'd be interested in seeing any combos with the 4.5" stroke, as well.