4L80E vs Allison 1000: Which Goes In Your Conversion Build

Building a HD project truck and choosing between 4L80E and Allison 1000? Both viable, very different cost and capability. Real decision factors.

Cost reality first

4L80E swap:

• Used core: $400-$900
• Rebuild: $1500-$2500 standard
• HD rebuild: $3500-$6000
• Wiring adapter / standalone TCM: $500-$1500
• Adapter housing: $200-$500
• Total: $2600-$8000

Allison 1000 swap:

Allison is 2-3x more expensive overall

Capability reality second

4L80E stock:

Allison 1000 stock:

Allison is stronger but 4L80E catches up with HD rebuild

Gear count and ratios

4L80E:

Allison 1000:

Bell housing patterns

4L80E:

Allison 1000:

For LS swap builds

4L80E preferred:

Allison harder:

For Cummins swap builds

Cummins to 4L80E:

Cummins to Allison:

For Duramax pulling Allison out

Why someone would:

Reality:

Physical size

4L80E dimensions:

Allison 1000 dimensions:

Heat capacity

4L80E:

Allison 1000:

Maintenance differences

4L80E service:

Allison 1000 service:

Tuning availability

4L80E:

Allison 1000:

Build cost by tier

4L80E Tier 1 (stock 600 HP):

4L80E Tier 2 (mild tune 800 HP):

4L80E Tier 3 (race 1000+ HP):

Allison Tier 1 (stock LB7 HP):

Allison Tier 2 (mild tune):

Allison Tier 3 (race 1000+ HP):

When to pick 4L80E

Conditions favoring 4L80E:

When to pick Allison 1000

Conditions favoring Allison:

Real builder experience

4L80E wins:

Allison wins:

Standalone trans controllers

4L80E options:

Allison options:

Truck buyer perspective

Buying donor truck (4L80E):

Buying donor truck (Allison):

Bottom line

4L80E for most builds:

Allison for serious HD:

Either works for most:

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Related:

• 4L80E HD rebuild
• Allison HD upgrades
• Rebuild vs replace