2. October Featured Powerplant: The LS3 427ci 625HP Stroker Crate Engine

When maximum modern muscle and everyday street manners need to merge into one package, look no further than our featured powerplant of the month: The LS3 427ci 625HP Stroker Crate Engine.

• Displacement: 427 Cubic Inches of brutal, reliable LS power
• Target Output: 625 Horsepower of pump-gas friendly performance
• Engineering: Built upon a heavy-duty aluminum block with premium rotating assembly components designed for maximum durability
• Standard Pricing: $17,090
• October Subscriber Special: Mention promo code NL at checkout to grab this beast for our special sale price of $16,590.00.

For full build specs, options, and block details, check out the package layout directly on our site at Proformance Unlimited LS3 Crate Engine Packages.

3. Tech Guide: Mastering Your EFI Fuel System (Pumps, Regulators & Line Sizing)

When upgrading to a high-horsepower fuel-injected powerplant like our 427ci LS stroker, your engine is only as good as its supply chain. An inadequate fuel system will starve your injectors under load, leading to dangerous lean conditions and potential engine damage. Here is how to configure your system right:

1. In-Tank EFI Pumps & Regulation: You must run a high-capacity in-tank electric fuel pump to keep the pump cool and quiet while preventing fuel starvation on hard acceleration or low tank levels. Because electronic fuel injection requires steady reference pressure, a bypass-style fuel pressure regulator and a dedicated return line back to the gas tank are mandatory. For most modern aftermarket EFI setups, you want to dial in and maintain 58 to 60 lbs of fuel pressure at the engine fuel rail.
2. Matching Fuel Line Diameter to Horsepower: Fuel line inner diameter (ID) matters significantly. As engine horsepower ratings climb, fluid friction increases, requiring a larger volume of fuel to travel without suffering pressure drop at the rails. Industry standards for supply (feed) lines paired with horsepower include:
   • Up to 600 HP: 3/8-inch or -06 AN line
   • Up to 800 HP: 1/2-inch or -08 AN line
   • Up to 1,000 HP: 5/8-inch or -10 AN line
3. The Return Line Rule: Your return line should run unrestricted from the regulator back to the tank. To prevent back-pressure that can disrupt your regulator’s operation, the return line should generally match your supply line size or be no more than one size smaller (e.g., a -08 AN feed can utilize a -06 or -08 AN return).