McLeod Racing RST HD Twin w/ Steel Flywheel - 2009+ GM LS-X 8 Bolt Crank - 1-1/8 x 26 - 168T
If you are building a boosted LSA or another 2009-up GM LS-X engine with the 8-bolt crankshaft flange and want a twin disc that still drives like a street car, the McLeod 6405807MD is the steel flywheel version of McLeod's RST HD. It pairs a twin disc clutch with a billet steel flywheel carrying a 168 tooth ring gear, splined 1-1/8 x 26 for the transmission side.
Two discs give twice the clamping surface of a single disc of the same size, which is how a twin holds big torque without a leg-breaking pedal. McLeod's RST HD discs are hybrids: one side is full-face organic friction for smooth, predictable engagement, and the other side is segmented ceramic for more bite under load. McLeod rates the RST HD at up to 950 horsepower with a lighter than stock pedal.
The steel flywheel is the reason to pick this part number over an aluminum one. Steel carries more inertia, so a heavy car pulls away from a stop with less slip and less throttle, it is more forgiving in traffic, and it soaks up heat better during repeated launches. If you care more about quick revs on a road course, the aluminum flywheel version suits that job better.
Put the car in a high gear at low rpm and apply full throttle. If the tach rises and road speed lags, the clutch is slipping. Rule out the hydraulics next: a soft or sinking pedal, low fluid or a leaking slave cylinder can keep a good clutch from fully engaging. Our slipping diagnosis guide covers telling clutch slip apart from other drivetrain problems, and the repair cost guide shows what the labor side of a clutch job runs.
McLeod describes this kit as fitting 2009-up GM LS-X engines with the 8-bolt crank, a 168 tooth ring gear and a 1-1/8 x 26 spline input. That covers engines such as the LSA, which debuted in the 2009 Cadillac CTS-V, and 8-bolt LS-X crate engines. It is not a vehicle-specific listing, so check three things: count the crank flange bolts (the earlier LS family uses 6), confirm your starter is set up for a 168 tooth ring gear, and confirm your transmission input is 1-1/8 x 26. Running a 6-bolt LS? Use the RST HD steel flywheel kit for 6-bolt LS engines. Want the lighter flywheel instead? See the RST HD with aluminum flywheel for CTS-V and C7. For more holding power, the 6405807M twin shares this 8-bolt layout. Send us your engine, transmission and VIN if you are unsure.
| Brand | McLeod Racing |
| Part number | 6405807MD |
| Fits | McLeod Racing RST HD Twin w/ Steel Flywheel - 2009+ GM LS-X 8 Bolt Crank - 1-1/8 x 26 - 168T |
| Type | Clutch Kits - Multi |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Not if your crank has the 6-bolt flange used by most earlier LS engines. This kit is for 8-bolt crank LS-X engines from 2009 up, such as the LSA. Count the flywheel bolts on your crank and buy the 6-bolt RST HD kit if you have six.
A steel flywheel stores more energy, so it makes heavier cars easier to launch and drive in traffic and handles heat from repeated launches well. Aluminum saves weight and revs faster, which suits track cars.
McLeod rates the RST HD twin at up to 950 horsepower. For higher power, McLeod's RXT and RXT HD lines use all-ceramic discs and higher clamp loads.
The discs are splined 1-1/8 x 26. Confirm your transmission's input shaft matches before you order, and send us the transmission model if you are not sure.
No release bearing is listed as part of this kit. Inspect or replace yours during the install, along with the pilot bearing.
