I've never understood how people get away with 5.3 swap cheaper. I mean by the time you spend 800-1000 on a 5.3, and buy the intake, injectors, rails, plugs. oil pan, windage tray, accesroy mounts, and a water pump to convert it to a ls1 style exterior, you may as well have bought an ls1/t56 combo already bolted together and not worry about sourcing a flywheel and clutch. As far as being out of your league, if you can handle a motor swap then dropping a 5.3 in over a ls1 isn't even a challenge. It's really just changing the bolt ons.