All production LS engines were fuel injected which means you’ll need to control the fuel and spark once it’s transplanted. It is possible to use the factory wiring harness and ECM, but our experience is that this is fairly complicated if you’re not a pro. A friendlier way to do it is with an aftermarket controller. This HP EFI system from Holley is easy to install and has several options for tuning including a self-learning routine. You can also connect a laptop to it and test your fuel and spark mapping abilities.