How much does it cost to LS swap a Jeep TJ?
Expect about $1,343–$2,913 in swap-specific parts for a Jeep TJ LS swap, before the engine (4L60E: $1,343; AX15: $2,913). Those are separate versions, not parts to add together: you buy the set for your transmission.
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The parts on our list for the Wrangler TJ / LJ (2026 retail prices; required unless marked optional):
- Novak KIT-LS-TJ-A-1 TJ LS kit, 4L60E, Foundation (5 parts) ($1,343)
- Novak KIT-LS-TJ-M-1 TJ LS kit, AX15 manual, Foundation (15 parts) ($2,913)
- Novak KIT-LS-TJ-A-2 TJ LS kit, 4L60E, Essential (18 parts) ($3,993) (optional)
- Novak KIT-LS-TJ-A-3 TJ LS kit, 4L60E, Complete (23 parts) ($4,723) (optional)
- Novak KIT-LS-TJ-M-2 TJ LS kit, AX15, Essential (25 parts) ($5,291) (optional)
- Novak KIT-LS-TJ-M-3 TJ LS kit, AX15, Complete (31 parts) ($8,170) (optional)
How the totals add up (required parts only):
- 4L60E: TJ LS kit, 4L60E, Foundation (5 parts), $1,343
- AX15: TJ LS kit, AX15 manual, Foundation (15 parts), $2,913
On top of this you'll need the engine (junkyard or crate) and, unless a kit above includes them, the transmission, wiring/ECU and tune, fuel system, cooling and exhaust. The whole-build budget is on the Wrangler TJ / LJ swap guide; price your own combination in the swap cost estimator and see how much an LS swap costs for typical ranges of each item.
Expect about $10,000 in parts, without labor, for a complete and reliable TJ swap; $3-4k is only realistic with strong fab skills and patience. An itemized Gen IV 4.8 + 6L80 + Atlas IV build we've seen came to about $11,080, with the Atlas IV ($3,500), Speartech harness/tune ($2,000), 6L80 ($1,500) and engine ($1,250) as the biggest items. The budget route is a Gen III 5.3 ($900), 4L60E ($300), Advance Adapters 4L60-to-231 adapter ($680) and Wayne Hartwig harness/tune ($450), for about $4k. Plan the engine/trans combo up front.
Check this first:
- A 6L80 requires a Gen IV engine
- A Gen III PCM will not happily run a TCM-controlled 4L70
Based on what we've seen work across our own builds, our friends' builds and the wider LS community, reviewed by our lead shop tuner (over 20 years of LS and LT tuning experience). Every combination is different, so use at your own risk.
Go deeper
Check this first
- A 6L80 requires a Gen IV engine
- Plan the engine/trans combo up front - the 6L80's internal T43 needs Gen IV CAN comms
Try this, then this
- Budget route: Gen III 5.3 + 4L60E + adapter + reworked harness — ~$4k path from the row. Worked if: you can fab and are patient
- Reliable route: Gen IV 4.8 + 6L80 + matched ECM/TCM — ~$10-11k, trans actually shifts. Worked if: ECM and T43 TCM are a matched set
How you know it's fixed
- Wording corrected: 4L70E is PCM-controlled (no internal TCM); 6L80E is TCM-controlled (internal T43)
Still not fixed?
- Running a 6L80 behind a Gen III PCM leaves the trans uncontrolled - use a standalone 6L80 controller or match Gen IV ECM+TCM
Key numbers
| What | Value |
|---|---|
| Gen III PCM controls engine AND transmission (no separate TCM) | single PCM |
| 6L80E TCM identity and location | T43, on the valve body inside the trans |
Time and cost: Weeks to months depending on fab skill