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SKU: FPE-LTR-FMJ-SD10X | UPC: 732777409808
Fleece Performance Freedom Series Solid Aluminum Full-Machined Billet Block - GM LTR Standard Deck (10X)
The Fleece Performance Freedom Series solid aluminum block provides the foundation for extreme-power Duramax builds that exceed the limits of factory cast-iron blocks. Precision CNC-machined from a single 1,000+ lb aircraft-grade 6061-T6 aluminum forging, this standard-deck block delivers unmatched strength, reduced weight, and superior heat dissipation while supporting 3,000+ horsepower applications with proper head retention and girdle systems.
Key Features
- Solid Billet 6061-T6 Aluminum Construction: No sleeves – fully machined from one solid forging for maximum rigidity and consistency.
- Standard Deck Height: 9.760" (same as factory LTR block) – direct replacement for 2020+ L5P and LTR engines.
- Extra-Thick Decks & Cylinder Walls: 0.750" minimum deck thickness and 0.500"+ cylinder wall thickness for extreme cylinder pressure.
- Bore Capability: Ships finish-honed at 4.125" (supports up to 4.250" bore with custom machining).
- Reinforced Main Webbing & ARP Main Stud Ready: Accepts ARP 625+ or custom main studs without modification.
- Improved Oil & Enlarged Oil Galleries: Enhanced lubrication paths for high-volume oil systems.
- Weight Savings: Approximately 95-100 lbs total block weight (vs. 215+ lbs for factory iron block).
- Made in the USA: 100% CNC-machined and inspected at Fleece Performance in Indiana.
Product Notes
- Part number: FPE-LTR-FMJ-SD10X (Standard Deck 10X version).
- Block is delivered finish-honed, decked, line-honed, and bored/honed to 4.125" with torque plate.
- Compatible with all factory LTR/L5P oil pans, timing covers, and accessories.
- Requires billet main cap girdle (recommended Fleece or equivalent) and head stud/fire-ring setup for extreme power levels.
- Camshaft bore enlarged to accept 65mm roller bearings.
- No provision for factory piston oil squirters (blocked off for competition use).
Installation Notes
- Intended for professional race engine builders only – requires full custom assembly.
- Deck surface finish: RA 15-20 for MLS or O-ring heads.
- All threads are cut, not cast – compatible with standard Duramax fasteners.
- Core charge does not apply – this is a new billet block.
This Part Fits
| Year | Make | Model | Engine | Notes |
|---|---|---|---|---|
| 2020-2025 | Chevrolet | Silverado 2500/3500 | L5P / LTR 6.6L Duramax | Standard Deck |
| 2020-2025 | GMC | Sierra 2500/3500 | L5P / LTR 6.6L Duramax | Standard Deck |
Why Choose Fleece Performance?
- Industry leader in high-horsepower Duramax components with proven 3,000+ HP builds.
- Every Freedom Series block is individually CNC-machined and inspected in-house.
- Trusted by top drag, sled pull, and diesel performance shops nationwide.
Frequently Asked Questions
- Q: What bore size does it come with?
- A: Ships finish-honed at 4.125" (stock L5P bore). Can be machined larger by your engine builder.
- Q: Does this block require a girdle?
- A: Strongly recommended above 1,500 hp mandatory above 2,000 hp for reliability.
- Q: Will factory L5P heads bolt on?
- A: Yes, same bolt pattern and dowel locations as OEM LTR block.
Shipping & Handling
- Method: Freight truck only (wood crated, fully insured).
- Package Weight: Approximately 180–200 lbs (block + crate).
- Crate Dimensions (approx): 42" × 28" × 28" reinforced wood crate with foam lining.
- Availability: Ships same day or next if in stock otherwise these are Built to order – typical lead time 8–14 weeks.
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