Slant 6 to 318 swap, 72 Duster, Using 75 D100

These are the 2 trucks for 2k. Also for just the 75 witch is the yellow, he said truck only with hood $800. What is an estimated guess on how much i will have to spend on a 318 or maybe a 340 with trans to be able to do this build. I was assuming that for the price of these the money needed for extra parts would be made back by resale the trucks after we are done swapping.