Gen 3 LSJ Short Block

Engine - Gen 3 LSJ Short Block
Engine - Gen 3 LSJ Short Block

Gen 3 LSJ Short Block

14 reviews
Regular price $2,799.99
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The Gen 3 block is a huge improvement for GM and solves previous shortcomings of the Gen 1 & 2 versions of the Ecotec engine. The block itself is an improvement over the LNF Gen 2 block, and can handle up to and over 500whp, however the rods are much weaker than an LNF. We generally see the rods fail at around 320-350 wheel torque on our mustang dyno (do note that all dynos read differently, so this range can change wherever you're testing), however differences in fuel quality, tuning, and driver/equipment setup and use can see failures earlier or later. If you want to make more than 350wtq we would highly suggest our upgraded rods and pistons. We offer a full forged engine here.

Improvements include:
-Cylinder wall bracing that prevents sleeves from breaking out in high HP applications
-Sand casting which removes porosity found in the older foam cast blocks
-5 pounds of additional aluminum adding internal structural support and solves the coolant jacket leakage issues with Gen 2 blocks

This is a fully assembled brand new short block, includes block, bearings, crank, DI pistons, & rings assembled as in the picture and a new oil cooler.  Does not include the water pump, timing chain assembly (guides/chain), or the front cover.  You will relocate your oil pressure sensor in the hole in the block below the oil filter housing close to the crank sensor.

Pistons/Rods Option: This engine comes standard with "DI" Direct Injection pistons which work fine in the LSJ, but we do offer a flat top stock compression ratio Diamond forged piston/ZZP rod option.

Important break in procedure:

We recommend running Comp Cams "break in" oil for the first 200 miles.  Before you start the car with the new engine, we recommend that you fill with oil, then leave the injector harness unplugged and turn engine over until the oil pressure light goes out, or even better, use an oil pressure gauge.  This ensures that you are starting the engine with full oil pressure. 

When the engine is running in gear and at light throttle, bring it up to 4500rpm, then coast down to near idle(still in gear), then 5000, then 5500, then 6000, and 6500 each time letting it coast down to idle.  This will help seat the rings. Then after a couple heat cycles, start running it under power.

Freight shipping details:

When you chose a freight shipping option, we use R&L Carriers.  Our website will email you a tracking number that you will have to enter into the "Pro Number" box on this website page:


These are built to order. Delivery will happen typically after 2 to 6 weeks after ordering. 

Customer Reviews
4.9 Based on 14 Reviews
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Jeremiah L.
United States United States


The experience was great. ZZP’s Ryan D. has been great. Engine arrived in great shape. Haven’t been able to run the thing yet, but all parts have bolt up just like they should. This thing should go great in my DF Goblin.

ZZPerformance Gen 3 LSJ Short Block ReviewZZPerformance Gen 3 LSJ Short Block ReviewZZPerformance Gen 3 LSJ Short Block Review
Bryan L.
United States United States

Vroom vroom

Depending in what route you go you might need a different size bolt or two,, but top notch customer service will help you figure that out.. Can't wait to get this finished and installed to replace the old block with 200,000 miles on it. Ready for a fast car powered by ZZP!

ZZPerformance Gen 3 LSJ Short Block Review
Duane N.
United States United States

Great product!

Very nice. Installed runs perfect! Thanks zzp!

Ryan M.
United States United States


If your using this block to replace a factory LSJ block and your keeping the Supercharger Setup, there are a couple things to consider not mentioned here: Comes with Direct Inject Pistons (it just says DI pistons) You can run the DI pistons with a port inject setup The upper 2 mounting bolt holes on the block for the Intake Manifold bracket are different (larger, M10-1.5x70mm is what you need) Because the mounting bolt holes are larger, the Intake Manifold bracket holes will need to be enlarged/drilled out to accommodate the larger bolts (I just used a hs drill bit and some WD-40, it’s aluminum fairly easy to do) And if your running a phenolic spacer, your spacer washers will need to be drilled out OR you can find equivalent stacked washers that are the same height. That’s about all I’ve run into so far.

ZZPerformance Gen 3 LSJ Short Block Review
Ryan M.
United States United States

One or two small things

Block came well packaged and undamaged, as advertised. However there are a couple things to note. Oil Cooler “thermostat” is not included, I’m assuming the LDK doesn’t run one, so I’m not going to run one. The 2 bolt holes for the upper IC bracket are not the same as the LSJ. Your gunna need an M10-1.5x 60mm, or 70mm, or 80mm, I have to go back to the damn hardware store tomorrow to figure that out since they closed after my last trip and I forgot about the phenolic intake spacer washers so 50mm I got are too short.

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