Are there a lot of these 99 engine still out there for good prices?

I heard of some other pullers either adding deck spacers or having billet blocks built to get to the 650ci range with these 99 motors but everything is always hush hush.

Maybe it would be a good adventure trying to build one of these with Deck spacers for the next beast to go into Diablo...... 1200hp sometimes just isn't enough.....