Fleece Performance Freedom Series solid aluminum LTR Duramax billet block front view
Top view of Fleece Freedom Series standard deck surface and cylinder bores
Side profile showing extra thick cylinder walls and main webbing on LTR Freedom block
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Fleece Performance GM LTR Freedom Series Standard Deck Solid Aluminum Block

FPEFPE-LTR-FMJ-SD10X
732777409808
Engines
2 Units In Stock - Ships Next Business Day
$ 6,850.00
$ 6,850.00

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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