LM4

[Editor’s Note: This LM4 engine upgrade guide is part of a series of LS engine upgrade guides assembled by a team of LS experts at Summit Racing that we’re sharing at OnAllCylinders. For […]

The LM4 is a 5.3L, Gen. 3 small block engine used in GM trucks between 2003 and 2005. It’s is very similar to the LM7, except that it’s built on an […]