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Vehicle Info NeededHOLLEYPART NUMBER: 510-558-486
558-486 M8 Service Harness for 6.86 in. and 12.3 in. Holley Pro Dashes
$14295
Ships on Sep 14, 2026
Lowest Price GuaranteeM8 Harnesses
M8 Service HarnessReplacement Harness for:
- 6.86 in. Holley Pro Dash
- 12.3 in. Holley Pro Dash
This Holley 558-486 M8 Service Harness will get your EFI system back to functioning as it did before the original harness was lost or damaged.
Part TypeWiring Harness
BrandHOLLEY
Package Height3.3
Package Width6.5
Package Length6.65
Weight0.46 PG
Part CategoryPerformance Parts
Part FitmentSei Universal
Vendor Part Number558-486
Package Qty1
Package TypeEA
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