Jim Carter Classic Trucks usually has rebuilt 261 short blocks for about $1500; all 235 parts (head, pan etc) will bolt right on. Langdon's Stovebolt Engine Co can also supply 261 rebuilds at similar prices.
Or for the ultimate "unfair advantage", you could build a 290 cu in 261 stroker as per Tom Langdon's article in the current 12 Port News.
Of course, a lot depends on how much money is on the line for this match race...
