Several folks on other forums have mentioned that the swap of a complete 5.3L engine and OD automatic from a 90's GM vehicle is very straightforward if you get all the electronics and wiring from the donor. Older carbureted SBC 350's usually need quite a bit of work to help the HP (better heads, newer manifold, etc.), while an injected 5.3L engine already has about 280 HP, and it even gets fairly good gas mileage. I assume you can say the same thing about the Ford 4.6/5.4 engine, since it was widely used in many cars and trucks.
The one major item I'm not sure about is how it would work with a CAN Bus system like I have in my 2005 Mustang. The computer seems to be tied to just about everything, and I don't know how that affects the swap. For example, the engine sensors send data to the computer, and my analog dash just displays the computer data. There is no direct connection from the sensors to the gauges, so I don't know how I would use anything other than the stock gauge panel. I don't even have a water temp sensor, since the computer gets input from a cylinder head temp (CHT) sensor and "calculates" the engine temp.
Last edited by 75gmck25; 11-20-2011 at 08:42 AM.