I wanted the V-3 unit that is self contained. It seemed like the easiest route. I couldn't find any used V-3s local to me but new I know they are around 4-5k for the V-3, not counting injectors, tune, BAP or aftermarket pump, and everything else I would need. I have less than that in this engine, and I wanted to keep it N/A. 460 RWHP is about the limit, even with a good tune, you can push a cast 4.6 4v bottom end. So if I wanted to make similar power to yours reliably I would also need to factor in the cost of a forged rotating assembly (close to another additional 2k). It is cool you have a Auto mach 1 too. I have one, mine is an 03 Torch red auto, I bought it for $5500 with 73,985 miles on it.