* Engine Bay Identification: The most reliable method is to look at the engine itself. LS engines have distinct features:
* Valve covers: Typically have a distinctive shape and often have the LS designation cast into them.
* Intake manifold: LS intakes are relatively low-profile and have a specific shape.
* Engine block: Look for casting numbers on the block. These numbers will definitively tell you the engine's model. You'll need to cross-reference these numbers with a GM engine code database to verify it's an LS.
* Oil filter location: The location of the oil filter is different on LS engines compared to other GM engines.
* VIN Decoder (Limited Help): While a VIN decoder can tell you the original engine the G20 was equipped with from the factory, it won't necessarily indicate if it's been swapped for an LS engine later. Factory G20s generally came with small-block V8s (like the 350 or TBI 454) but very few came with LS engines from the factory.
* Documentation: If you have any service records or purchase documentation, that might list the engine type.
* External Clues (Less Reliable): Some people modify their G20s to look a certain way, so while these are *hints*, don't rely on them:
* Performance modifications: If the van has significant performance upgrades, an LS swap is more likely. But it could also be something else.
In short: The only truly reliable way to determine if a Chevy G20 has an LS engine is by visually inspecting the engine and verifying the casting numbers. Any other method is just circumstantial evidence.
