LQ4 Budget LS Swap Guide — Cheapest Path to V8 Power

The LQ4 and LQ9 are the least glamorous LS variants and the most bang-for-buck engines in the junkyard. Pull one from a 2000–2007 GMT800 truck or van for $500–800, and you have a 360 hp iron-block monster as your starting point.

Identifying your engine: LQ4 is a 6.0L iron block rated at 300–325hp stock. LQ9 is also a 6.0L but came in higher-spec trucks (Escalade, Denali) with better heads — rated at 345hp. Both accept the same mods. VIN decoding or casting number checks confirm which you have.

Step 1 — Cam swap: The stock truck cam is tuned for towing torque, not power. A Texas Speed Stage 2 cam (224/228 duration, 0.600 lift) transforms the LQ4 into a legitimate performance engine. The cam swap is straightforward with a degree wheel and basic tools.

Step 2 — Heads: The factory truck iron heads are restrictive. Porting or swapping to a set of LS6 or cathedral port aluminum heads wakes the engine up dramatically. Texas Speed CNC-ported LS6 heads are $1,100 a pair installed.

Step 3 — Intake manifold: Replace the truck intake with an LS6 or LS9 manifold. The cathedral port intake from a Corvette/GTO or a Holley Hi-Ram makes a significant difference.

With cam, heads, intake, long tube headers, and a quality dyno tune, the LQ4/LQ9 easily makes 430–480whp on pump gas. Add a shot of nitrous or a small power adder and you are well over 500whp on a $6,000 total budget.