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Chevrolet/GMC C1500 / K1500 OBS LS swap (1988–1998)
Swap kits verifiedGMT4001 sourced swap recipe
LS Gen III/IV swap — moderate
1988–1998 GM OBS C/K 1500/2500 LS swap: Dirty Dingo slider mounts (2WD/4WD), adjustable 2WD trans crossmember, AC brackets (PSI catalog).
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| Part | What | Price | ||
|---|---|---|---|---|
| Crossmember | PSI Conversion 88–98 Adjustable 2WD C1500/C2500 Automatic Transmission Crossmember (crossmember) | $244.99 PSI Conversion, 2026-09-28 | Required | |
| Mounts | Dirty Dingo 2WD LS Slider Engine Mounts DD-2550C | Required | ||
| Mounts | Dirty Dingo 4WD LS Slider Engine Mounts DD-2575-4 | Required | ||
| Accessory drive | Dirty Dingo LS R4 A/C Compressor Accessory Bracket DD-LS-R4-AC-TR | Optional | ||
| Accessory drive | Dirty Dingo LS Sanden A/C Compressor Accessory Bracket DD-SANDEN-AC-TR | Optional | ||
| Driveshaft | PSI Conversion Adapter to mate a 1350 U-joint yoke to a 3-bolt differential (yoke adapter) | $54 PSI Conversion, 2026-09-28 | Optional | |
| Wiring & ECU | PSI Conversion 99–07 Gen 3 LS/Vortec (24X) Engine Controller Kit, drive-by-cable, w/ 4L60E-75/4L80E control (standalone harness, MAF, flashed ECM, bracket) (Gen 3 24X DBC kit) Ready-to-run option; flashed for application | $1,099 PSI Conversion, 2026-09-28 | Optional |
Required parts we've priced so far: $244.99 (parts only, not a full budget — engine, trans, wiring and labor are extra. Try the swap cost estimator.)
LS swap parts listed for the C1500 / K1500 OBS
Vendor catalog listings matched to this vehicle by product title. Prices as last checked; confirm fitment with the vendor.
| Type | Product | Vendor | Price | Stock | |
|---|---|---|---|---|---|
| Mounts | Transmission Crossmember - 88-98 C1500 Silverado | ICT Billet | $200 | In stock | View |
| Mounts | Motor Mount Rubber - SBC 4wd 88-98 Chevy Truck | ICT Billet | $20 | In stock | View |
| Headers Exhaust | LS Headers 88-98 2wd OBS 78-87 G-Body | ICT Billet | $380 | Out of stock | View |
Swap kit evidence
- LS Conversion Engine Swap Mounts ... 1973-1987 Square Body 1988-1998 OBS Chevy GMC Truck (search title) — Amazon (3rd-party) (kit-listed)
- PSI - OBS Truck LS Swap Parts — PSI Conversion (kit-verified)
Questions about this swap
Every LS swap also needs
An oil pan that clears
Compare GM LS pans by sump position and depth.
Accessory drive spacing
F-body, car, truck and Corvette offsets.
Fuel system sizing
Injector and pump sizing for your power goal.
A transmission
4L60E to 8HP70 behind an LS.
- PSI - OBS Truck LS Swap Parts — PSI Conversion