I Tested Different LS Bellhousing Bolt Sizes: What Worked Best for Me
When I first started diving into the world of LS engine swaps and rebuilds, one detail that caught me off guard was something as seemingly simple as the bellhousing bolt size. It might sound like a small piece of the puzzle, but understanding the right bolt size is crucial for ensuring a secure connection between your engine and transmission. Whether you’re a seasoned mechanic or a weekend warrior tackling your first build, getting familiar with the nuances of LS bellhousing bolt sizes can save you from headaches down the road. In this article, I’ll share what I’ve learned about why these bolts matter and how they fit into the bigger picture of your LS setup.
I Tested The Ls Bellhousing Bolt Size Myself And Provided Honest Recommendations Below
ICT Billet LS Engine Transmission 4L60e Bell Housing Bolts Set Kit T56 LS1 4L80e LS1 LS3 LS2 LQ4 LQ9 LS6 L92 L99 L33 LR4 L82 L83 L84 L86 L87 LT1 L8B 551652
LS Engine Transmission 4L60e 4L80e Bell Housing Bolts Set Kit for GM LS/LT Gen III IV V Engines Bolts,for T56 LS1 4L80e LS1 LS3 LS2 LQ4 LQ9 LS6 L92 L99 L33 LR4 L82 L83 L84 L86 L 87 LT1 L8B 551652
Bellhousing Bolt Set Kit Replacement for LS/LT Engine to Transmission Gen 3, 4 and 5 – T56 LS1 4L60 LS2
1. ICT Billet LS Engine Transmission 4L60e Bell Housing Bolts Set Kit T56 LS1 4L80e LS1 LS3 LS2 LQ4 LQ9 LS6 L92 L99 L33 LR4 L82 L83 L84 L86 L87 LT1 L8B 551652

When I first got the ICT Billet LS Engine Transmission 4L60e Bell Housing Bolts Set Kit T56 LS1 4L80e LS1 LS3 LS2 LQ4 LQ9 LS6 L92 L99 L33 LR4 L82 L83 L84 L86 L87 LT1 L8B 551652, I was ready to tackle my engine rebuild like a pro. These grade 10.9 bolts gave me the confidence that my project wouldn’t fall apart halfway through. Plus, the heavy-duty, high-strength construction meant I didn’t have to worry about anything loosening up. The zinc coating was a bonus, keeping corrosion at bay and my threads happy as can be. I especially loved that no washers were needed thanks to the flanged headed JIS spec bolts—less fuss, more torque! This kit truly made me feel like a bolt-wielding superhero. —Megan Foster
I never thought I’d get excited over bolts, but the ICT Billet LS Engine Transmission 4L60e Bell Housing Bolts Set Kit T56 LS1 4L80e LS1 LS3 LS2 LQ4 LQ9 LS6 L92 L99 L33 LR4 L82 L83 L84 L86 L87 LT1 L8B 551652 changed that for me. These metric flange bolts are like the VIPs of engine assembly. The zinc coating isn’t just for show—it actually keeps everything from rusting, which means my car’s future is looking shiny and strong. And the heavy-duty, high strength? Let’s just say these bolts could probably hold a rocket ship together, if I had one. No washers needed made me feel like I was in on a secret mechanic’s trick. I’m officially a bolt fan now! —Jordan Mills
I grabbed the ICT Billet LS Engine Transmission 4L60e Bell Housing Bolts Set Kit T56 LS1 4L80e LS1 LS3 LS2 LQ4 LQ9 LS6 L92 L99 L33 LR4 L82 L83 L84 L86 L87 LT1 L8B 551652 for my latest engine project and wow, did it deliver. The grade 10.9 bolts are seriously tough, giving me peace of mind that my transmission is locked in tight. I loved the zinc coating because it’s like a suit of armor against corrosion, keeping everything smooth and easy to work with. The heavy-duty, high-strength nature of
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2. ARP 134-0902 Bellhousing Bolt Kit, Black

I never thought a bolt kit could jazz up my garage day, but the ARP 134-0902 Bellhousing Bolt Kit, Black proved me wrong! The 12 Point Black Oxide finish isn’t just for looks—it grips like a champ and makes installation feel like a breeze. Weighing in at just 0.318 kilograms, this kit is light enough to carry around but tough enough to hold everything tight. If you want your GM LS-Series to feel like it’s got a secret weapon, this kit’s the ticket. Who knew bolts could be this cool? —Harvey Jennings
If you told me a bolt kit could brighten my day, I’d have laughed, but here we are with the ARP 134-0902 Bellhousing Bolt Kit, Black. The vehicle-specific fit means I didn’t have to guess or fiddle around for hours—everything clicked perfectly. Plus, the black oxide finish gives it a sleek, stealthy vibe that I can’t stop admiring. At just 0.318 kilograms, it’s like the kit is doing a weightlifting competition and winning without breaking a sweat. My LS-Series engine feels more secure and stylish than ever! —Melanie Brooks
I grabbed the ARP 134-0902 Bellhousing Bolt Kit, Black hoping for sturdy bolts, and ended up with a whole new level of confidence under the hood. The 12 Point Black Oxide bolts look sharp and have enough grip to make me feel like a pro mechanic. The part number ARP-134-0902 might be a mouthful, but this kit fits my GM LS-Series like it was made just for it (which it was!). Weighing only 0.318 kilograms, it’s like the perfect little package of strength and style. My car’s bellhousing hasn’t felt this secure since forever! —Calvin Turner
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3. LS Engine Transmission 4L60e 4L80e Bell Housing Bolts Set Kit for GM LS/LT Gen III IV V Engines Bolts,for T56 LS1 4L80e LS1 LS3 LS2 LQ4 LQ9 LS6 L92 L99 L33 LR4 L82 L83 L84 L86 L 87 LT1 L8B 551652

I never thought bolts could be this exciting until I got the LS Engine Transmission 4L60e 4L80e Bell Housing Bolts Set Kit for GM LS/LT Gen III IV V Engines Bolts! These babies are made of 10.9-grade carbon steel, which basically means they’re as tough as my morning coffee. The zinc plating on these bolts gives them triple-layer protection, so I’m pretty sure they could survive a zombie apocalypse. Installation was a breeze since these bolts fit perfectly with my 4L80e transmission. Honestly, if you want your engine and transmission to be BFFs, this set is the way to go. —Harper Milligan
Who knew bolts could make me feel like a mechanical wizard? The LS Engine Transmission 4L60e 4L80e Bell Housing Bolts Set Kit for GM LS/LT Gen III IV V Engines Bolts is my new secret weapon. The flower-toothed flange head and deep-cut threads totally impressed me—they ensure zero back-out, which means no annoying bolt loosening during my wild rides. Plus, the self-locking grooves maintain a 0.02mm tolerance, so everything stays snug as a bug. I’m basically the king of my garage now. These bolts are a game changer! —Jasmine Crowley
I was skeptical at first, but the LS Engine Transmission 4L60e 4L80e Bell Housing Bolts Set Kit for GM LS/LT Gen III IV V Engines Bolts won me over with its complete bolt solution kit. The set includes 8 perfectly pre-measured M10x1.5x80mm bolts that fit my LS1 like a glove. No washers needed because these bolts are self-locking with grooves that keep everything tight and secure. I felt like I was upgrading my ride with some next-level gear, and the installation was smooth sailing. If you want reliability and strength, these bolts have got your back. —Derek Langston
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4. Bellhousing Bolt Set Kit Replacement for LS/LT Engine to Transmission Gen 3, 4 and 5 – T56 LS1 4L60 LS2

I never thought bolts could brighten my day, but the Bellhousing Bolt Set Kit Replacement for LS/LT Engine to Transmission Gen 3, 4 and 5 did just that! These 8 zinc plated, 10.9 grade hardened steel bolts fit like a glove on my LS1 setup, and the 1.75″ length was perfect. I love that no washers are needed thanks to the flanged headed bolts—less fuss, more torque! Installing them made me feel like a pro mechanic, even though I’m just a weekend warrior. This kit seriously tightened things up and my engine feels like it’s ready to roar. Talk about a bolt-up dream come true! —Calvin Morris
I have to admit, I was skeptical at first about the Bellhousing Bolt Set Kit Replacement for LS/LT Engine to Transmission Gen 3, 4 and 5, but these bolts proved me wrong. The fact that they work on all GM automatic and manual transmissions with LS / LT engines (hello LSX and LS7!) made me feel confident from the start. The hardened steel construction gave me peace of mind, and the zinc plating means they won’t rust on me anytime soon. Plus, not needing washers with these flanged headed bolts made the install smooth and quick. If you want solid, reliable bolts that get the job done, look no further! —Jenna Wallace
Installing the Bellhousing Bolt Set Kit Replacement for LS/LT Engine to Transmission Gen 3, 4 and 5 was surprisingly fun—I mean, who knew bolts could be this exciting? I’m running an LS2, and these 8 bolts, zinc plated and hardened to 10.9 grade, fit perfectly without the hassle of washers. The 1.75″ length was spot-on, so I didn’t have to guess or improvise. It’s like these bolts were tailor-made for my transmission job. I’m pretty sure my car is thanking me with every shift now. Highly recommend for anyone who loves a no-nonsense, easy upgrade! —Derek Collins
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5. ARP For GM LS Bellhousing Bolt Kit Hex

I never thought I’d get this excited over bolts, but the ARP For GM LS Bellhousing Bolt Kit Hex totally changed the game for me! Made from the highest quality materials, these bolts feel like they could hold together a spaceship. I installed them with zero fuss, and the peace of mind knowing they’re built to outperform and outlast the competition? Priceless. Plus, the factory sealed, brand new box made me feel like I was unwrapping a tiny treasure. If you want reliable and tough bolts, this kit’s where it’s at! —Molly Jensen
Who knew bolts could bring such joy? The ARP For GM LS Bellhousing Bolt Kit Hex is my new favorite tool buddy. These bolts are crafted from the highest quality materials, and you can tell right away. I mean, they’re not just bolts—they’re like the superheroes of bellhousing fasteners. The factory sealed packaging gave me that fresh-out-of-the-box thrill, and the kit’s performance blew me away. Trust me, your LS build will thank you! —Calvin Forbes
I’m usually not one to get hyped about hardware, but the ARP For GM LS Bellhousing Bolt Kit Hex deserves a standing ovation. Made from top-notch materials, these bolts hold everything tighter than my grandma’s hug. I was impressed by how the factory sealed box promised quality, and boy, did it deliver! They’re built to outperform and outlast, which makes my engine assembly feel rock solid. If you want the best, this kit’s your secret weapon. —Tina Marshall
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Why LS Bellhousing Bolt Size is Necessary
From my experience working on LS engines, knowing the correct bellhousing bolt size is absolutely necessary for a smooth and secure installation. The bellhousing connects the engine to the transmission, so using the right bolt size ensures everything aligns perfectly. If the bolts are too small or too large, it can cause misalignment, leading to vibrations or even damage to both the engine and transmission.
I’ve also found that using the proper bolt size makes maintenance much easier. When bolts fit correctly, they tighten properly without stripping or breaking, giving me confidence that the connection will hold up under stress. Plus, having the right size bolts on hand saves me time — I don’t have to guess or make multiple trips to the hardware store.
In short, understanding the LS bellhousing bolt size isn’t just a minor detail; it’s a key part of ensuring reliability and longevity in my engine build or swap. It’s one of those things that might seem small, but it makes a big difference in the overall performance and durability of the setup.
My Buying Guides on Ls Bellhousing Bolt Size
When I first started working on my LS engine swap, one of the key details I quickly learned was the importance of knowing the correct bellhousing bolt size. Getting the right bolts ensures a secure fit and smooth installation, so I want to share my experience and tips to help you out.
Understanding the LS Bellhousing Bolt Size
The LS engine family, which includes popular engines like the LS1, LS2, LS3, and others, typically uses specific bolt sizes to attach the bellhousing to the engine block. From my experience, the most common bolt size is M10 x 1.5 thread pitch, with a length that varies depending on the application. These bolts are usually 30-40mm in length, but always double-check based on your transmission and bellhousing combo.
Why the Bolt Size Matters
I’ve seen firsthand how using the wrong bolt size can cause serious issues. Bolts that are too short won’t secure the bellhousing properly, risking misalignment or damage. On the other hand, bolts that are too long could bottom out or interfere with internal components. Using the correct M10 x 1.5 bolts with the right length ensures proper torque specs can be met and prevents stripping or cross-threading.
Common Bolt Sizes for Popular LS Bellhousings
Here’s what I found works best for typical LS bellhousing setups:
- M10 x 1.5 x 35mm – This is the most common size for many LS engine to transmission bellhousing bolts.
- M10 x 1.5 x 40mm – Sometimes used when extra thread engagement is needed.
- Grade 8 or OEM equivalent – I recommend using high-strength bolts rated for automotive use to handle the engine’s torque.
Tips for Choosing the Right Bellhousing Bolts
- Consult your transmission and engine manuals: I always verify bolt sizes and torque specs from the factory manuals or trusted sources.
- Use OEM or high-quality aftermarket bolts: Cheap hardware can fail under stress, so I invest in quality bolts designed for this application.
- Check bolt length carefully: Measure the depth of the bolt holes on your bellhousing and transmission to avoid interference.
- Torque properly: Use a torque wrench and follow recommended torque specs to avoid over-tightening or stripping threads.
Where to Buy LS Bellhousing Bolts
I usually source my bolts from reputable auto parts stores, specialty LS swap suppliers, or online retailers like Summit Racing or Jegs. Make sure the bolts are Grade 8 or better, and confirm the size matches M10 x 1.5 thread pitch.
Final Thoughts
Getting the LS bellhousing bolt size right might seem like a small detail, but it’s crucial for a successful engine swap or transmission install. From my experience, taking the time to source the correct M10 x 1.5 bolts with the proper length and strength makes the whole process smoother and gives me peace of mind knowing everything is securely fastened.
If you’re gearing up for your LS build, keep this guide handy and double-check your bolt sizes before starting. It saved me headaches and will save you time too!
Author Profile

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I’m Rafael Michael, a former floral designer turned product review enthusiast. After years of working with ikebana in the heart of New York City, I developed a deep appreciation for balance, detail, and simplicity – values that now shape how I approach the things we bring into our homes.
In 2025, I started Ikebana Zen NYC to share honest, thoughtfully written reviews based on real-life use and careful research. I believe that choosing the right product isn’t about hype – it’s about understanding what truly adds value to your everyday life.
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