5.3L LSx build in Indy
Thread Starter
Teching In
Joined: Jan 2019
Posts: 4
Likes: 0
5.3L LSx build in Indy Hello from Indy! New to the LS engine community but not to the SBC crowd. Wanting to find out from the guys who have used the 5.3L cast iron truck block as a starter for a nice LSx performance build, how this idea sounds: I'm pulling my 2003 LM7 from my Yukon and am wanting to rebuild and modify it to produce around 430Hp to 450Hp naturally aspirated with very good mid-range torque. It's going to end up replacing the L98 TPI engine in my 1986 Corvette. Here's what I'm thinking about doing... bore the block from 96mm to 99mm (5.7L), install LS6 heads, LS6 intake & throttle body, and LS6 fuel rail & injectors... port and polish the heads and install a nice aftermarket cam (not sure which one yet) and control it all with an aftermarket ECM. I welcome all thoughts and direction on this idea... 
TECH Senior Member
Joined: Jun 2016
Posts: 22,293
Likes: 3,617
From: Central Cal.
Get a nice CNC porting job on the heads (nobody polishes anymore, BTW). This assures a VERY consistent port-to-port match. There are a TON of good cams to do what you want. Best here is to call the grinders themselves and get a recommendation from them. Cam Motion, Texas Speed and Performance, Brian Tooley, among others. Also give WS6store a call for good deals on all the overhaul parts needed. They also handle cams and can give a good recommendation.
