An LS series engine (e.g., LS1, LS2, LS3, LS6, LS7, LS9) will fit just fine. The tunnel needs to be widened for a custom 4L60E 4-speed overdrive automatic and the "x"L60E series of tranny's are just too big unless you want to use a torch to open up the tunnel. The LS engine hit the steering gear box so I went to rack-n-pinion steering, which turned out to be a MAJOR pain to eliminate bump steer. The rack was installed on the custom engine cross member that holds the custom engine mounts. Did I mention the custom tranny mount as well as a custom shift linkage?
This is the FrankenBenz, the car I've been working on *forever* with an LS6/4L60E bolted in place. The rack-n-pinion is installed, the custom drive shaft is there attached to the custom 3.07 LSD differential. The custom fuel pump (Walbro) is installed. Yet to do is the custom drive-by-wire throttle pedal, custom wiring harness, SEC radiator with Z06 Vette dual electric fans. A custom dual-exhaust will have to be fabricated.
Please note the numerous uses of the word "custom" - this isn't easy, there is no "kit", you will have to do it all yourself. When this is done, I'll have an SEC with around 480hp that should have better gas mileage than stock. The engine isn't stock either, which upped the HP from stock 405 to a dyno reading of about 480.
No modifications are expected to the hood and I'm planning on using an MB skid plate underneath. Other than a Lorinser chin piece and rocker panel add-ons, the SEC will look stock.