Glad to see another Dodge getting scrapped and the only good part going into a Chevy. I love my 68 K20 with a 12 Valve. Tons of torque and great mileage!
A side note: I strongly encourage you to run U bolts over the rear axle as I wouldn't trust bolts holding down the axle once you play with the torque of the motor. Other than that it looks awesome and this is the fan I used for mine:
http://www.speedwaymotors.com/Ultima...-80,42296.html
91015682 from Speedway Motors; expensive but it fit the stock Dodge radiator very nicely and when it actually has run (rare unless a trailer is hooked up) it easily cools off the engine. I have very little room between my engine and rad and it works great.