5.3L Build Advice

[Bryan Spear]

Hello,
I just received a used Chevy 5.3L Vortec engine (LM7) out of a 2003 Silverado. Everything on it is stock at the moment and I would like to build it so that it can produce more than the stock 300 HP and keep it naturally aspirated if possible. I was already considering changing the cam, intake , and throttle body but would like to know what others have done with these engines and what's recommended. Thank you.

[asilverblazer]

If I'm doing a cam swap, I'm going to hit all the valvetrain with upgrades.

 

Intake and throttle body aren't going to be big power sources. However those are pretty easy to do - as part of a full bolt-on process, tune, headers, CAI, intake manifold and throttle body, exhaust, maybe some bigger injectors, colder t-stat for more aggressive tuning.

 

That should be a pretty potent engine without pulling heads.

[swathdiver]

3 hours ago, Bryan Spear said:

Hello,
I just received a used Chevy 5.3L Vortec engine (LM7) out of a 2003 Silverado. Everything on it is stock at the moment and I would like to build it so that it can produce more than the stock 300 HP and keep it naturally aspirated if possible. I was already considering changing the cam, intake , and throttle body but would like to know what others have done with these engines and what's recommended. Thank you.

 

As the old saying goes, how much do you got to spend and how fast do you want to go?  As ASilverBlazer said, there's a bunch of stuff mentioned that contributes little or nothing to performance.

[CamGTP]

Do a camshaft and headers with a tune. Add an intake if you want. I'd probably go with slightly larger injectors just to be safe.

 

Keep the stock throttle body and intake manifold. Should be an easy 35-40hp with cam and headers.

 

Stock thermostat is just fine, no reason to run a colder one.

[Bryan Spear]

What are some headers you recommend to go along with a cam?  Thanks.

[CamGTP]

What's your budget?

[Supreme Pizza]

[swathdiver]

On 1/13/2022 at 10:10 PM, CamGTP said:

What's your budget?

 

Zero or was he too impatient to answer questions for a thoughtful answer?

[Bryan Spear]

I apologize for not replying sooner.  If you are asking about a budget for headers, I'd say I'd like to keep it under$600.  Thank you.

[CamGTP]

I haven't checked prices in a long time but Speed Engineering headers are still rather cheap and the next step up are Texas Speed headers. Past that you are talking $1,000+ for some headers more than likely.

[shakenfake]

Speed engineering is $430 for headers and y-pipe x-pipe may be a bit more expensive

[Bryan Spear]

16 hours ago, CamGTP said:

I haven't checked prices in a long time but Speed Engineering headers are still rather cheap and the next step up are Texas Speed headers. Past that you are talking $1,000+ for some headers more than likely.

 

Any idea if those vendors will clear Novak engine mounts in a Jeep Wrangler TJ frame?  Thanks.

[CamGTP]

No idea. They are made for truck frames. Anything else is a complete toss up.

 

You'd have to contact someone who has done a swap before to see if it's possible.