1974 Dodge Dart Swinger Hardtop engine swap

I found a 1968 340 bored .30 over with a TCI 727 in my area for $3900 and wanted to know if it was a good price for that motor and transmission and if it would add value to my 74 dart, also if it would be worth the swap from the slant six and 904. Also wanted to know if you would be willing to help out with it, if yes how much would you charge? Thanks. Also should note the guy selling says the motor has 2000 miles on it and 1000 on the transmission. What other parts would I need besides the K member, mounts, and maybe better front suspension? What would a good rear end be for the car, the rear in the dart is stock so it'll definitely have to go. I've read on another forum that 68 340s were rated at 270hp 5000rpm, but the dyno results the seller posted looks like the max is 224 at 4900, the engine looked to be somewhat cold when it was tested so that might have something to do with it. Also it comes complete except for the starter, would I be able to use any small block starter?