Todd G.

The LS accessory drive you choose sets your belt path and your clearance to the frame, steering box, hood and radiator. Truck, Corvette, and F-body layouts are spaced differently and are not freely mix-and-match. Here’s how to pick the right one for a swap and avoid pulley-alignment headaches.

The #1 LS-swap oil-pan mistake is choosing by “front-sump vs rear-sump” instead of by chassis. Here’s what actually determines pan fit — crossmember, steering, engine position, and 2WD vs 4WD front-diff clearance — plus the real story on the Holley 302-2 and how to pick a pan for a Squarebody, OBS, or GMT800.

A real LS swap budget isn’t one number — it’s a stack of decisions. This guide breaks cost down by donor completeness, controller strategy, transmission, chassis, and labor, so you can build a figure for your build instead of copying someone else’s total from a different truck, year and region.

Not “which LS is best” — which LS is best for your goal. Budget, towing, big naturally-aspirated power, simplest wiring, lightest weight, or a factory six-speed: each pick names the exact RPO, controller, transmission and the trap to avoid, drawn from our verified engine dataset.

The definitive Gen III vs Gen IV comparison for swapping LS-family engines into older Chevy and GMC trucks. Engine generation, electronics, crank/cam signals, controllers, throttle, VVT, AFM, heads, fuel, oil pans and transmissions — treated as separate attributes, with the transition-year exceptions that break every simple rule.

A pre-purchase identification procedure for LS-family donor engines: find the RPO, decode the VIN, read block castings, and confirm crank reluctor, cam-sensor location, throttle type, controller, transmission and fuel system before you spend a dollar. An intake cover is not proof of what you’re buying.