For as long as we can remember, the base powertrain of the Express/Savana twins was the 4.8L Vortec V-8 L20 mated to a GM Hydra-Matic six-speed heavy-duty automatic transmission (MYD).

In Part 2 of our 383 Stroker LS Build we assemble and dyno test our 4.8L Vortec V-8 Stroker Motor after being stripped, cleaned, and machined in Part 1.

On the oily bits front, the 4.8-liter Vortec V8 (L20) is no longer available. The replacement is a naturally aspirated V6 (LV1 V6) that develops 265 horsepower and 295 pound-feet at 4,000 rpm.

GM 383 Stroker LS V8 Build: Part 1 Adding Displacement to a 4.8L Vortec V-8 for Reliable Power HOT ROD StaffWriterMay 12, 2014 See All 29 Photos ...

Transmission, 4-speed automatic electronically controlled with overdrive and tow/haul mode (STD) (Included and only available with (LY2) Vortec 4.8L V8 SFI engine with Active Fuel Management.) ...

The shop started with a very low mileage 4.8L salvaged from a ’01 Silverado pickup. The Vortec LR4 engine is a small-block engine used from ’99 to ’06.

Required with (LU3) Vortec 4.3L V6 MFI engine, (L20) Vortec 4.8L V8 SFI FlexFuel engine, and (L96) Vortec 6.0L V8 SFI FlexFuel. Available with (LMF) Vortec 5.3L V8 SFI engine.

According to GM's 2010 Fleet Guide, the company is dropping the naturally aspirated, 367-horsepower, 375-pounds-feet-of-torque, 6.0-liter V-8 L76 Vortec engine from its Chevrolet Silverado 1500 ...