BIG INCHES BIG FUN

THIS HIGH-COMPRESSION 427 LS MAKES SERIOUS POWER ON THE DYNO.

- STEVEN RUPP

By now, the HOT ROD audience knows there are a ton of ways to build an LS engine for big power. Given the versatility of the LS platform, how do you decide which way to build it? The first thing you need to ask is how you want to use it. If hard handling is in your future, then saving weight by going with an aluminum block makes sense. Of course, saving weight in a drag application helps, but it's not nearly as critical and makes not a lick of difference in a street cruisier application. The benefit of an iron block is strength, which moves up the priority list quickly if you're considering boost or some nitrous in your future. An iron block, even an aftermarket version, will also be quite a bit less expensive compared to the equivalent aluminum version.

We wanted to build a rowdy LS for a Chevelle that was 80 percent street cruiser and 20 percent weekend-warrior drag car. Given these parameters, the smart bet was an iron block, and since we wanted a decent amount of displacement, we opted for an iron LSX block from Chevrolet Performance. It's vastly less expensive than an aftermarket aluminum block and has a lot of improvements over a stock OE block. Here's one way to build a large displacement LS engine with an abundance of power and decent street manners.

01 The Chevrolet Performance Parts LSX Bowtie iron block (PN 19213964) from Summit Racing offers quite a few features not found on factory LS blocks. Improvements include extra head bolt provisions, thicker deck surfaces, and other refinements like improved bay-to bay breathing, doweled main caps, a seventh transmission bolt hole, and a priority-main oiling system.