First-Gen F-Body Gen-III LS1 Engine Swap - Generation Zap Part 1

There has been a movement within our hobby over the last several years to update vintage iron with an eye toward modern-day performance, reliability and, most importantly, drivability. Call it Pro Touring, G-Machine, Restomod, MuscleRodTM or what-have-you, advancements in automotive-based engineering, design, electronics, and materials has fostered this cause. Modern transportation can be quicker and quieter, have better handling and braking, and be more efficient than the musclecars of yore; 40-some-odd years of progress will do that.

While many in the hobby embrace the-in-your-face attitude of our Pontiac musclecars and their brutal unabated power surge and resulting roar when the gas pedal is mashed into the loop pile carpet, others yearn to bridge the gap between vintage style and modern utility, power and poise, 10 mpg and 25 mpg.

They want to participate in events like the Hot Rod Power Tour and other long distance cruises, where their cunning efforts of injecting new-age performance into a classic musclecar can be appreciated. They take pride in staying true to their hot rodding roots, but do not have to endure 98-degree cockpit temps, 4,000 cruise rpm and $60 fuel stops every 200 miles.

HPP has published many stories on these Pro Touring type Pontiacs that use a traditional Pontiac engine mated to an OD transmission to get the revs down on the interstate, factory or aftermarket A/C to keep the interior cool and upgraded suspension, brakes and tires to either reach or surpass the handling capabilities of modern muscle.

Taking the idea of modernizing one a step further, this '69 Firebird convertible will be fitted with a Gen-III LS1 engine-the standard powerplant for the '98-'02 Trans Am and Formula. With horsepower ratings ranging from 305 to 320, the LS1 was developed by GM Powertrain and is not an updated small-block Chevy engine, even though many claim it is. The all-aluminum engine is a clean-sheet-of-paper-design. The fact that GM refers to it as a small-block and that it was also in the Vette, Z28, and Chevy trucks fuels the fire that it's a rehashed Bowtie engine. The attributes of the LS1 have been discussed at length in HPP, so we won't labor the point further here. Suffice it to say that it puts out solid power numbers, is lightweight, and represents the best GM technology that was available when designed.

The '69 Firebird convertible belongs to HPP contributor and owner of Classic Restoration Enterprises, Melvin Benzaquen, and the swap will be performed at his facility. Since this Pontiac will exhibit a Pro Touring theme, Brewer Restoration and Performance (BRP) was tasked with upgrading the existing '69 subframe with one of the company's First-Gen LS1 subframe conversion kits. Installation of BRP's kit will not only allow easy mounting of any LS-series engine, but it will also modernize the suspension, braking and steering systems.

Part I will cover the subframe mods and bolting the engine and six-speed trans in to check for proper clearances. In Part II, the electronics, linkages, and accessories will be discussed and an aftermarket A/C unit will be installed.

Decisions, Decisions
As with any other major undertaking, there are a million decisions to be made. Of course, there are cheaper ways to go about this swap, and there are much more expensive ones. Ours represents a middle-of-the-road approach that will satisfy the goals of the owner and not break the bank.

For instance, an LS7 swap would be great since they're all the rage right now for ultimate performance in an LS-series engine. A GMPP crate motor, however, costs approximately $13,000 and more expense will be incurred in changing over other LS7-specific items that will not work with LS1 or LS2 six-speed trans. Conversely, Melvin paid $4,500 for both the 900-mile LS1 and its six-speed trans, which were extricated from a wrecked F-body. The objective isn't to install the most powerful LS engine ever, but rather to modernize the car. If LS7 power is desired at a later date, supercharging, turbocharging, or nitrous are still options.