ls_dan

Hi, I am new to the LS world. Just bought a 200,000 mile LM7 and I am getting ready to tear down and rebuild of the motor. I am not sure what I am going to put it in when I am all done, but I am working on that. I do have a few ideas rolling around in my head.

The engine does run and did not hear any knocking before it was pulled. I will do a compression/leak down later this week, but I can already tell that compression feels good.

My question for you guys is what should be done/needs to be done on a high millage motor like this on the rebuild? I was planning on a full rebuild kit for the bottom end. But what is necessary and what should I leave alone?

As for the power, I am not looking for anything crazy. Just looking to get about 500+ HP, maybe even with a turbo. I still want it to be daily drive-able. I know that I want an upgraded cam, but what should I be looking for (remember, I want it to idle nice and be a good daily) I may be throwing it in a Trailblazer sized SUV. I want to keep this build on a budget, so I am not looking to go overboard, I just want it to be solid and get some extra power out of it.

Let me know what you guys think.

Treyvs

To pull 500whp N/A out of a 5.3, you'll need some serious air to flow through the engine, meaning you'll be spending serious money on ported heads, cam and intake. As for at the bottom end goes, putting in some H rod bearings would be good insurance. New cam bearings also since they're cheap and can dramatically impact oil pressure if you pair a new cam with old/loose bearings. Texas Speed sells some solid ported 5.3 heads for $1299 outright and can pair them with a good cam/spring package for Under $2000. Expect to pay $800-$1000 for an intake and matching throttle body. With the machine work and parts, figure a budget of around $3500 for everything. If you do end up trying to touch the bottom end, figure $5000. Even after all this being invested, you'll probably still be around 425whp. 500 will come when you add boost or spray.

tech@WS6store

iTrader: (2)

Build the 5.3l into an iron 5.7 and have a better starting point.

We have a complete rebuild kit for iron 5.7s that runs $699. Comes with an engine build book also.

That would be your best bet to start. Then you can treat it like and ls1 and go from there and make much more tq and hp to begin with

ls_dan

Thanks for the quick reply's.

When I say 500HP, that's with boost not N/A. I am just looking for suggestions for what to replace on the bottom end while I am in there. I hear some people talk about the "magic" and not messing with some things. Just wanting to know should I just go nuts and replace all rod and main bearings, as well as, cam bearings? I am also planning on honing the cylinders and replacing rings. Do the rods need to be upgraded, will stock not handle 500HP+? I am hearing from multiple people that the stock bottom end should handle much more.

I would also like some suggestions on cams to use for decent power upgrade but also be street-able and be happy with the addition of a turbo later down the line.

tech@WS6store

iTrader: (2)

Our high lift hot cam is perfect for great NA power and boost later also! great sound too.

Id bore it out and put ls1 flat tops in. The only difference would be torque plate bore/hone really.
If you are going that far, reusing old pistons is a waste really. All that work just to reuse parts that are worn?

The rods will be fine to 500ish.