Automatic Transmissions

Automatic transmission options for LL8 swaps - direct bolt-on and adapted solutions.

4L60E

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Bolt-On: Direct bolt-up to LL8, no adapter needed

Availability: Very common, inexpensive

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Issue: Notoriously weak transmission

Solution: Can be "built" for reliability, but still limited

Recommendation: Consider TH400/4L80E for higher power builds

Stronger option requiring adapter plate - recommended for high power applications.

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Adapter Plate: Converts LL8 bellhousing pattern to TH400/4L80E

Hub Adapter: Makes up distance created by adapter plate

Flexplate: May need to redrill to match torque converter

Spacers: Custom length spacers for torque converter bolts

Bellhousing Notch: May need to notch bellhousing depending on adapter design

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TH400: Requires custom hub adapter for proper spacing

4L80E: LS hub adapter will likely work (hub is further forward)

Available: Emtech Motorsports sells hub adapters with different neck heights

Short neck for 4L80/6L80, long neck for PG, TH350, 400, 700R4, 200R4

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Emtech Motorsports: Laser cut/CNC machined adapter plates (3/8" thick)

Includes side flanges for mid-engine mounting (recommended for 500+ lb-ft)

Torque Converter Spacers: Supplied by Emtech as of Jan 2025

Starter Adapter: Available from Pohill Racing or Emtech (works with Tilton starter)