GMPP LS7-Powered 2004 Pontiac GTO - Dept X: GM Performance Parts' LS7 GTO

No matter what your opinion is of the styling or its ability to live up to the GTO mystique, it's really hard to argue with the '04-'06 GTO as a performance platform. It features a spectacular chassis, great brakes, slippery aerodynamics and a luxurious interior-and the driveline is first-class. If you're looking for a basis for a modern, high-performance automobile, one that will do everything well, it really is one-stop shopping.

Though dealers in various parts of the country reportedly still have new units in their inventory, we have heard from more than one retailer that demand for used GTOs is on the upswing, especially the '04s. It seems that they are being seen as a relatively low-cost starting point for high-performance buildups. So what if the '04s don't have the scooped hood-that upgrade can be added later.

Dr. Jamie Meyer, GM Performance Parts' product integration manager, recently invited HPP to the company's facility in Grand Blanc, Michigan, to demonstrate just what a sweet package their LS7-powered '04 GTO is. More than just a pie-in-the-sky concept car, this Goat is a machine that any enthusiast can replicate using a combination of over-the-counter and aftermarket parts.

Even though the bright yellow GTO has been pressed into duty for the LS7 conversion, it has spent its entire life as a developmental mule. It was never even assigned a factory VIN-a hand-painted "CUS201" is located at the base of the windshield where a factory VIN tag would normally go. This time around, the GTO was used as a testbed to science out the swap from the stock 5.7-liter LS1 to the Z06 Corvette-spec LS7.

The process of the conversion was twofold, first integrating the engine to the chassis and second, beefing up the driveline and rear suspension to handle the extra 155 horsepower.

One might think that since both engines come from the same family, the swap would be as simple as replacing a 326 with a 455. Not quite. There's more wiring and electronics and a different oiling system, but GMPP has used this car as an engineering/development mule to take the mystery out of installing an LS7 crate engine.

The Engine Swap
In order to facilitate the upgrade process, GMPP enlisted the help of BMR Fabrication, who helped simplify the swap and also provided components that beefed up the rear suspension and differential.

First off, the fitting of the dry-sumped LS7 in the GTO required a custom engine cradle. BMR has developed, with GMPP, an engine cradle that provides sufficient clearance for the dry-sump pan. Originally, the stock front cradle was used, and the oil pan was modified to fit. With the new cradle, the oil pan remains stock. The swap necessitated the use of a custom oil reservoir, which is located in the engine compartment where the stock battery went.

Integrating the LS7 with the GTO's stock wiring harness has now been greatly simplified with a kit to install and plug in, which also allows the stock E67 controller to accept custom calibrations for the LS7 engine.

According to Dr. Meyer, the ultimate goal is to offer, through GMPP, the LS7 engine with an E67 controller and the necessary wiring harness that will make it possible to install any LS series engine into any application, even an older carbureted vehicle. The controller will require an accelerator pedal with a position sensor.