Snowman,
Most junkyards will just about give away a 6 cylinder HEI. I bought two for $25. Disassembled both and cleaned up the best one, got a new cap and rotor from the Zone for $20. The hookup is alot easier than you think, basically it's as easy as T Lowe says. I checked the module from the second unit I bought - it is good and in the glove box.
The increase in performance is substantial - you won't be unhappy.
