It’s no secret that GM LS engine respond with aggressive horsepower gains when they can breathe more air. The factory EFI systems restrict the LS engines air intake flow. A good example of this is what we found when dyno testing the GMPP 5.3L 327CID crate engine. The 5.3L made a respectable 327HP @ 5500RPM and 347 ft/lbs @ 4600RPM with the stock LS3 GM EFI system. We swapped the LS3 EFI out for the Edelbrock 7118 intake kit and bolted on Edelbrock’s 650CFM carb. With this carb & intake the 5.3L woke up and made 350HP @ 5600RPM and 370 ft/lbs @ 4100RPM. That is a 7% gain before any fine tuning. With today’s advancements in carburetor and intake casting technology putting a carb on your LS engine is an affordable way to get the most out of LS engines.