The LS4 engine has not been a popular choice when it comes to an LS-swap. The powerplant offers several challenges, whether you are trying to use it in a front-wheel-drive (FWD) or rear-wheel-drive (RWD) application. In a FWD configuration, you are limited to the type of transmission you can run in stock form, with the LS4 4T65eHD being your only option. Like the 4L60e, the 4T65eHD is underwhelming in performance and tends to bring a premium when purchased at a junkyard. For a RWD setup, you will have a couple of problems. One is that the engine block does not have any provisions for mounting the starter. The second problem is the LS4 has a specific bolt pattern for the 4T65 transmission and will not bolt up to a 4l60e, 4l80e, TH400, etc. One area of the LS4's design that can open up some possibilities is with the oil pan.