The 5.7 hemi swap is really dang near close to bolt on these days if it's any consolation. In the earlier days when people were still figuring things out and developing parts it was pretty expensive and labor intensive, but I swapped a 5.7 into my 67 Dart and the only thing I had to modify was to trim the input shaft on the transmission (kept the A833 I had in the car already). The engine fell right into the motor mounts and headers, while incredibly close on tolerances, fit in pretty good without much fighting. I went the carb route on it for the time being because I didn't want to drop a ton of money on updating the fuel system, though I'm looking into converting back over to EFI since I had a Megasquirt computer fall into my lap for the right price.
I talked to a guy at a car show nearby that had a 78 Aspen that did a fairly stock 360 Magnum swap (I think he did a cam and some home port cleanup) and it was a pretty nice deal. I haven't got my car tuned very well yet, but when we paired them up he would hold with me pretty good till my engine wound up. For what it's worth I like the 5.7 swap because I think the engine has a lot more potential. You can get 400 hp in one with just a cam and the stock block and crank are good for quite a bit more. Throw in a set of heads and your talking 450-500 pretty easy for not a lot of money on a stock bottom end.
As far as price it really boils down to just what you want to do with it. I swapped in my 5.7 with a carb to get it back on the road for between $5000-6000 with the engine included. I got some good deals along the way, but I also ran into a bunch of extra money for parts I didn't originally think I would need. The main thing you need to do is really look at what you're starting with to try to account for the little things or things that aren't engine related. For instance, if you have power steering currently you'll have to swap over to manual, so be ready to drop money on a new steering box. I believe power brakes are a possibility, but manual for sure fits easier. You can make stock manifolds fit for way less than TTI's, but it's up to you what you want to do with it. Shop around for the right engine complete with wiring harness and computer (mine came without, another reason for the carb swap), and you're one step closer to being able to dang near drop the engine in and go.
