LS versions have the top bellhousing bolt at 12 o’clock and use a 300 mm input/converter. Earlier non-LS units lack the top bolt and use a 298 mm converter.
1998+ F bodys, like Camaros, Firebirds also 1998+ Corvettes, 1999–2006 LS trucks/SUVs and the 2007 Classic Silverado/Sierra 1500. In 2007 new-body (GMT900) trucks, GM moved to the 4L70E. 2007 full-size SUVs (Tahoe/Suburban/Yukon) were new-body only—no “Classic”—so they typically use the 4L70E.
Check for the top 12-o’clock bolt and verify the 300 mm converter spec. Provide your VIN at checkout and we’ll validate before build.
Yes. Each package includes a matched 300 mm LS-spec converter (billet upgrades available on Sport/Track tiers).
We configure solenoids/valve-body for your year. Perform a crank/PCM relearn after install for best results.
Always flush or replace the cooler and lines to protect the new unit and maintain warranty coverage.
Order the correct output/tailhousing. If you’re changing configurations, let us know—we’ll build it to your setup.
Coverage is listed per tier—up to 6 Years / Unlimited Miles. Extend can continue protection after the Monster term.
*HP figures are guidance; vehicle weight, tires, gearing, load, and tuning affect capacity. When in doubt, step up a level.
Jump to: Fitment & 300mm converter • 4L65E vs 4L60E • Common failures • Cooling & temps • Install checklist • PCM relearn/adaptives
The LS 4L65E is commonly searched as a “4L65E transmission for Silverado” or “LS swap 4L65E.” The key identifiers are the LS-pattern bellhousing (top 12-o’clock bolt) and the correct 300mm converter/input setup. If your truck/SUV is 2WD vs 4WD, output/tailhousing must match. If you’re unsure, VIN verification is the fastest way to confirm.
The 4L65E is essentially the heavier-duty evolution of the 4L60E family used behind many LS applications. Depending on year/application, it commonly includes stronger internal strategy and hard-part upgrades compared to earlier 4L60E builds. For most buyers, the right move is simple: match the unit to your vehicle weight, tires/gears, towing load, and tune.
The usual suspects are heat, converter slip, and stressed hard parts. High-intent searches you’ll see include “4L65E sun shell failure,” “3-4 clutch burn,” and “4L65E shudder.” Monster builds address those pain points with tier-appropriate clutch capacity, shift control strategy, and converter selection to keep apply events clean and temps stable.
If you tow, drive in hot weather, run bigger tires, or just want max life, treat cooling as mandatory. Confirm strong cooler return flow, run fresh fluid, and consider a low-restriction auxiliary cooler. A clean cooler/line path protects your new transmission and helps preserve warranty coverage.
After installing a fresh unit, the PCM may need time to relearn shift timing and pressure control. Clearing adaptives (when applicable) and running a sane drive cycle—light throttle upshifts and gentle coastdowns— helps the trans settle in and keeps fresh clutches happy.
For LS-pattern 4L65E applications, yes—converter size and spacing matter. All Monster packages include a matched converter for the build level.
Some 2007 “Classic” trucks stayed 4L65E, while new-body GMT900 half-tons moved to 4L70E. Verify with VIN to avoid ordering the wrong unit.
StreetMonster is the usual sweet spot for towing and mild bolt-ons. If you’re heavy, geared, or on sticky tires, step up to SportMonster.
Cooling + correct fluid level + clean cooler/lines + proper converter behavior. Those four items prevent most “it failed again” stories.
*Power guidance varies by vehicle weight, tuning, tire load, and duty cycle. When in doubt, step up a tier.
