Billet LT1 Bullet – An Inside Look at One Unusual Impala SS


photos by: the car’s unnamed owner

When we say, “tons of fun” we literally mean TONS. That’s because this ’90s nostalgic beast comes in at right around 4,500 pounds! For those keeping track that’s two and a quarter tons. Let’s put a little bit of this into perspective, folks. Taking a 4,500-lb car into the low 9’s takes some serious lug guts – that’s 9.2 seconds at 156 mph. If you had a similarly-powered Camaro – or whatever you fancy – that weighs in roughly 3,000-lbs you’re well into the 7’s territory.

So what’s the magic bullet that powers this chubby cousin? A one-off supercharged billet LT1 (the ’90s LT1, not the new one) motor that’s most definitely one of one ever made. We’ve checked and no one, literally no one, makes an LT billet block. So, why all the madness you might ask?

All in the name of consistency, brother. You see, the owner wanted to keep everything in his Impala SS stock, and he wasn’t kidding. The car boasts a full interior with power seats, ice cold AC, carpet, sound deadening, fully functional rear bench seat (for the ladies of course) and a headliner. The LT block simply completes the goal of being “stock.” From the outside the car looks like pretty much every mid ’90s Impala. The roll cage has been carefully tucked upside the pillars and the window net folds down easily for easy concealment. Under the hood is where all the bovine excrement stops.

impala-008-1050x787The one-off billet LT block was planned and designed by the owner with the help of some nasty talented machinists. Since the owner wanted to make big power, the stock block had to go. The stock block would literally start to twist under the immense pressure, which in turn would cause the rings to seat improperly; ergo, power loss. The billet aluminum block simply doesn’t deflect like the stock GM block does. The owner tells us, “because it’s made from a solid piece of aluminum you can do almost anything you want with it.”

With a 4.000-inch or larger bore, deck heights starting at 9.025 to 9.500, solid filled or full water cooled, 11 or 15 degree valve train, 55mm or 60mm cam bore, your choice of rear main seals and dry or wet sump oiling choices. We are told the options are virtually limitless and can take relentless amounts of abuse. It’s a fair statement that the block doesn’t really make the power; it just holds it in like an eggshell.


A number of things in a custom-built block don’t just “bolt up” like a stock block or one you get from your favorite mail order catalog. A lot of holes had to be drilled and tapped, many others had to be custom fit. “Everyone thinks these things just bolt up, but that’s not even close to the case.” The oil pan had to be modified, all the bracketry had to be custom fit and even the valve covers needed modifying.

“At the horsepower level I want to operate at, [switching to an LS] really would not have saved much money. You end up changing almost everything to build a quality LS engine at 1500 HP and up, so if you’re already buying all new expensive parts then the cost is not so different. That’s what this car and engine are all about. Take what others would replace or throw away because they say it won’t work and alter it or fix the problems to make it work. I also like to have something different and a one-of-one motor is about as unique as it gets.  It comes down to a personal decision at the end of the day.”


Here’s the $10,000 problem, when you run these big numbers, you need bigger parts and hiding those big parts under the stock valve cover is a problem when you want to run the stock hood and taller valve covers pretty much ruin that idea. “Dropping the tails of the shaft rockers, changing the adjusters to a smaller thread and nut, changing the bracing inside the valve cover to clear everything and windowing by the tail of the rockers in the valve covers makes it work.”

He continued, “Truth is, if Moroso or one of the other [aftermarket companies] made the changes I did to the valve cover anyone could put shaft rockers on with the same valve cover dimensions as stock even using a center bolt valve cover. This setup even shortened my pushrod length which improves the valvetrain. I just received my special built Trend pushrods yesterday. They are not normal pushrods and are designed around what’s needed for this engine.”


Oh, and the real fun part? The dude is running the stock Opti-Spark! Yep, that’s right. That giant turd of an ignition system is powering the supercharged porker. “If you build them right, you never have to worry about them. I’ve never had a problem with my Opti-Spark units.” Somehow, he’s found a fountain of youth we are very unaware of (To be fair, it wasn’t so much the Opti-Spark itself that typically caused failures, but more commonly, the water pump would leak and take the Opti out with it. -Ed.).

The owner kept the wet sump oiling system and the stock location oil filter. This gave more flexible options when it came to a number of factors. Remember, this is supposed to be “streetable” right? Still, when it comes down to it, when y’all are going to the track and it’s time to get a Whataburger, guess who’s race car you’ll be piling in the back of?


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