You can probably find a cheap 318 that you can put in there temporarily.
JK, I don't have any small block parts so I'd need a tranny also, then convert the DS to length. It's much cheaper just building the 440 for me.
The 440 for sale would still need machine work and such so it really isn't any better than just using the extra block I have.
If I really got in gear, it is possible to get it done in time for Carlisle, but it would be too much stress on me waiting for parts and then assembling everything. The one thing that I hate the most is busting butt for a deadline and then not making it due to lack of a part or just not enough time, that would bum me out more than just not doing it.