Engine Swap Checklist – Coyote vs HEMI vs LS

A step‑by‑step pre‑flight for modern V8 swaps: measurements, parts, wiring, first start, and tune logs.

Project Info

Goals & Constraints

Reliability first (conservative tune, quality cooling/oiling)
NA focus (gearing & manifold matched)
Boost plan (fuel system, intercooler, ring gaps if building)
Emissions / inspection compliance required
Keep A/C and power steering
Track days / oil control priority
Daily drivability in traffic and heat
Minimal cutting / reversible install

Pre‑Swap Assessment

Measure engine bay: width at towers/rails, firewall to core support, hood clearance
Steering and brake booster clearance (headers, starter heat)
Verify subframe/K‑member compatibility or swap options
Plan accessory drive (low‑mount A/C/alt near rack)
Oil pan choice clears crossmember/center link; baffling for track
Trans tunnel size and shifter position
Driveshaft length, yoke, and U‑joint series; pinion angle
Cooling stack space (radiator, fans/shroud, condenser)
Exhaust route past steering/suspension; cat placement if needed
Electrical: battery location, main power, grounds plan

Parts & Subsystems

Engine & Mounting

Complete long block with intake & throttle body
Swap mounts / adapter plates & crossmember
Oil pan & pickup matched to chassis; windage tray/baffle
Accessory drive brackets (low‑mount options)
PCV/vent catch can & hose routing
Sensors: MAP/MAF/IAT, crank/cam, knock, O2s

Transmission & Driveline

Clutch/torque converter matched to torque & use
Bellhousing, pilot, release system (hydraulic/MECH)
Trans crossmember & mount
Cooler & lines (auto/manual track use)
Driveshaft built & balanced to power level
Rear gear ratio set for tire height & rpm band

Cooling

Radiator sized for power; sealed ducting to core support
Dual fans with full shroud & relay control
Thermostat, hoses, steam ports (LS), overflow
Oil cooler & power steering cooler (track/tow)

Fuel System

In‑tank or external pump sized for hp & fuel type
Filters (pre/post), ethanol‑safe hoses, heat shielding
Regulator (return/returnless strategy), rails
Injector size for hp & E85 if used

Intake & Exhaust

Cold‑air intake placement with heat shielding
Headers/manifolds clear steering & starter; O2 bungs placed
Catalysts / mufflers (as required), hanger strategy

Electrical & ECU

ECU/PCM or control pack (Coyote/HEMI/LS), labeled harness
DBW pedal mount & wiring
Main power distribution, fused circuits, clean grounds
Wideband O2 gauge or CAN integration
Alternator/Battery charge wiring verified

HVAC & Steering

A/C compressor & lines (frame/rack clearance)
Power steering pump/lines, cooler, and rack fittings
Heater core plumbing/valve

Chassis, Brakes, Suspension

Brake upgrade (pad compound, rotor size, bias)
Springs/shocks rated for front weight; bump‑stop clearance
Subframe connectors, torque boxes, mounts (poly/solid)
Wheel/tire fit and speed rating

First Start & Break‑In

Pre‑Start

All fluids filled & bled; no leaks (fuel, oil, coolant, PS)
Prime oil system; verify pressure with plugs out
Base tune loaded; injector data correct; sensor sanity check
Throttle/DBW and clutch/neutral safety verified
Exhaust clear; fire extinguisher on hand

Initial Run

Idle learn complete; fans cycle; temps stable
Timing and lambda safe; no knock; fuel trims reasonable
Bleed cooling system; re‑torque clamps

Break‑In & Post‑Run

Heat‑cycle plan followed; early oil/filter change
Re‑torque headers, suspension, and driveline fasteners
Log drivability; schedule dyno/final tune

Tuning Targets (starter)

Values vary by combo; use conservative timing and watch IAT/ECT. NA vs. boosted strategies differ.

Notes