This All-Wheel Drive Firebird Packs a 6-71 BLOWN 5.3L LS

10 min read

This All-Wheel Drive Firebird Packs a 6-71 BLOWN 5.3L LS

10 min read

You might recall that we recently sat down with Gregg Hamilton, Hoonigan’s chief mechanic, to chat with him about his resto-modded ’78 Firebird. Well it turns out that’s not the only second-gen F-body in Hamilton’s stable, and even at a glance, it’s obvious that he had an entirely different vision for this ’71 Firebird Formula 400 build.

“I’ve always had a thing for these cars,” Hamilton tells us. “And because it’s a gen-two GM thing, there’s a lot of stuff around for them anyway, so that makes it a great base to start with.”

While perusing online car ads back in 2015, one particular listing caught his eye. “I happened to see one on Craigslist – it was out in Sandy Valley, which is about 45 minutes from here, and it was just sitting in some guy’s field. The price was reasonable and I thought it could be a good project to take on.”

After trailering it back to the shop, Hamilton started brainstorming. “There wasn’t really a clear plan – at least up to a point. But we had Ken’s Mustang, and that car is a great thing. I’ve had a chance to drive it a couple of times, doing shakedowns and things like that, and it’s a fairly inspiring car when you’re in it or seeing it go. So I thought maybe I could build something that was along those lines a bit, but wasn’t a million-dollar car.”

One of the Hoonicorn’s [Ken's AWD Mustang] hallmark features is that it sends the power to all four corners rather than just the rears, as a traditional Mustang drivetrain normally would. That not only makes for twice the tire smoke, it also gives Ken more precise control over the 1,400hp turbocharged and methanol-injected drift machine. “You can’t beat the grip of all-wheel drive when you’re working with tons of power,” says Hamilton.

“You can only put so much power down through two wheels no matter what you do. And I come from a rallying background – I’ve driven quite a few rally cars over the years, so that kind of setup has always been something I love and understand. And I wanted to do something a bit different with this car.”

"You can't beat the grip of all-wheel drive when you're working with tons of power". - Gregg Hamilton

After cooking in the Nevada sun for a number of years, Hamilton knew the Pontiac was going to need a lot of work to become road-worthy again, and that provided a great excuse to pursue some unconventional ideas along the way.

“I had wanted to do an independent rear suspension for the black Firebird, so I figured I could mock it up in the yellow car without having to take the black one off the road. Then I thought, well, I might as well give the four-wheel drive idea a shot while I was doing that. So I started heading to junkyards, grabbing bits and pieces here and there to help figure out whether or not I could make it work. And before too long, it started to look like I could do it. So it just sort of morphed from making the rear end for the black car with the yellow one, to ‘let’s cut the center out of this thing and mount the engine and gearbox.’”

Hamilton started hunting for drivetrain hardware that could do the job, this time turning his attention to eBay. “I noticed there was a lot of Skyline stuff for sale,” he says. “A few years ago, before you could bring in the Japanese Nissan Skylines, there were a lot of transmissions and things like that available online, and the R32 gearbox looked like a good option – they seemed to be able to take a fair bit of power.”

From there the Frankenstein approach only deepened. The LS-powered Firebird now sits on C6 Corvette crossmembers at the front and rear, and the front differential is actually a rear differential from an Infiniti Q45. “I had everything lined up on the floor and it looked like it would all fit – I could move the engine back far enough to get a front diff in it and run the driveshafts how I wanted to,” Hamilton explains. “So it was one of the projects that sort of slowly gathered speed as I collected all the things I needed to bring it to life.”

He essentially started at the center of the car and built outward, piecing together the chassis and drivetrain, installing a rear differential from a 300ZX out back, and fabricating fuel tanks, sections of the subframe, and pieces for the rocker arm front suspension.

The car is outfitted with custom QA1 coilovers at all four corners, while stopping power is provided by the brake system from a C6 Corvette Z06. A Nissan ATTESA center differential from an R33 Skyline is paired with an aftermarket control unit to manage the torque split between the front and rear wheels.

What started life as a 5.3L truck engine, the powerplant is now adorned with a Weiand 6-71 supercharger and controlled with a Holley Dominator EFI system.

Eventually Hamilton turned his attention to the power plant. “Along with four-wheel drive, I knew I wanted a Weiand 6-71 on it, because those are cool. But the pulley is a big problem here because the front differential is right there, and it’s in the middle – it’s not offset in that car. And you need a fair bit of space to make room for a blower pulley.”

He notes that it was worth the effort, though. “From the driver’s seat, it looks like you’re looking out of the windshield of an old Funny Car or something.” Underneath the 6-71 lurks a 5.3-liter iron block LS that’s been outfitted with a cam and heads from Texas Speed.

For the engine management system, Hamilton turned to Holley Performance. “We’re running the Dominator ECU – I really wanted that Holley digital dash in it. I also liked that fact that you can buy the bits locally, and it’s such an easy setup to work with and tune.” Running 11 pounds of boost, he estimates the mill is good for about 600 horsepower.

The end result is part Hoonigan and part Road Warrior, both aesthetically and mechanically, and Hamilton readily admits that he never had any intentions of appealing to the concours restoration crowd. “You’re going to upset every purist in town with a build like this anyway, so you might as well have some fun with it.”

So what’s next for the Firebird? That’s still up for debate, actually. “Maybe fender extensions, but I think it looks pretty good as it is,” he says. “We sort of accidentally made it look okay, and I wonder if that might screw it up. It’s constantly evolving, though – we’re always doing something to it. Right now it’s really just about dialing it in more, doing some smoky donuts, and going from there.”


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