LS3 Engine Build Question

[tiznodd]

The main difference between the LQ4 and LS3 is going to be the aluminum block. It's about an 80lb difference. Otherwise, with LS3 heads and an intake on the LQ4, you would be close in terms of power. A used cam would wake things up quite a bit too. 02-04 Z06 cams can be had for $100 these days. The compression would be the main difference at this point, more so than the .2 in displacement.

LQ4s are most popular with the forced induction guys because they are 9.4:1 compression, and seem to hold up well. If its a pre 2005, the rods are typically the first thing to go. People start bending them in the 750hp range. On the 2005+ they received the LS2 style rods and seem to hold up better. If spinning past 6500, rod bolts are a necessary upgrade as well.