That's me. Here are some pics a little info.
http://www.geocities.com/pipeline/reef/1549/wj.html
It was relatively easy. And there is lots of room. I looked at putting a Yamaha 650 in there, but it was going to be more work and more money spent to do it. And I already had the 650 kaw. engine.
I had a machine shop weld the couplers and make the bed plate, which was nothing more than 1/8' Stainless steel bent at the proper angle from each side. I can give more info if anyone's interested. It was a fairly light and quick. I imagine if a 650 would fit in there, so would a 750. It ran 45mph after I put a 44mm carb and a Mariner head. Great for jumping and sliding.
Walt, did you get to look at it when you picked up the X2 hull?
Jeff