[AceX]

I haven't started a thread yet. No reason to until major work starts, but I am slowly gathering parts.

For the fuel system, you'll need all new lines and fitting that can stand the MUCH higher pressure of a fuel injection system. You'll also need to swap out the switching valve assembly, fuel pump(s), and figure out a return system. All of this can be done using OEM parts. I'm ordering mine from S&P.

The ECU and harness (from most companies) will allow you to run the engine independently from any other system and will also have provisions for a check engine light, ODBII and diagnostic port, everything you need/want. Speartech, S&P, and Current Performance all have these options and harnesses available for LS1 through LS9.

I'm not sure if you will have to smog the motor or not, but if you do, be prepared to spend many hours chasing down sensors and codes. EVERYTHING from the donor car/truck has to be swapped over and working just as if it were the original vehicle. Cats, EVAP, EGR, MAF, and A.I.R. (if applicable). Some refs won't even allow headers. Check your state's smog laws and regulations for a better idea of what you're up against.

As far as a bigger motor, check the local yards. Many of them will have 5.3, 5.7, and 6.0 motors available with "low" mileage on them. Some wreckers even offer a warranty on some motors. I know that a 5.3 with >50k miles can be had for $1100 with acc., harness, and ECU. A 6.0 would run a little higher, but not much.

For a drive shaft, I'm not sure what you can do. I'm having one custom made, but that's because I'm also rockin' a 6L80E and a new 6.2L from a 2007 Escalade. If I had to wager a guess, I would say that no, you will not need to have a shaft(s) made, but I haven't done a whole lot of research in this area yet.