Sixtyfive, swapping from the 230 or 250 is very easy, if you had the 292 it's a little different. I've done this swap many times on these old trucks. Everything will swap over, including your bellhousing, flywheel, starter, clutch and pressure plate. The 283 may have come with a larger clutch, but if yours is in good shape it should work just fine. The engine mounts are actually the same, they just used a bracket between the six cyl engine block and the V8 mounts. Just unbolt the rubber mounts and bolt them to the V8. The only thing you might need is the clutch linkage ball. On the six it is usually welded to a bracket that bolts to the block. For the V8 you will need a screw-in style linkage ball, and it will screw into the 1/2" hole forward of the oil filter. The 283 should still have the forward hole, some of the newer 305's and 350's only had the rear hole. I think some of the parts stores may still have them in their "help" section.
Other than that all you should need would be exaust. Your fan will be pretty far from the radiator, but unless you let it idle for a long time you shouldn't have a problem. If you do then you may have to find you a shroud or just do away with the fan all together and run an electric fan.
Either way, it really makes a neat swap. Best of luck and if you need any more help just ask.
