biggness

I just recently "downgraded" from a 2015 LML Duramax to a 2018 L83 in a RWD GMC Sierra Crew Cab. I had a fair bit of work done to my old Duramax and do miss the insane torque when you mat the pedal, as well as the exhaust tone that I can only describe as a marriage of fighter jet and a T-Rex.

I've been out of the gas engine scene for a fair amount of time, and pretty much need major guidance on getting this 5.3 to be a fun little street truck, with some nice chop and deep tones, that can give fits to unsuspecting vehicles lol

Here is what I am looking to do:

-Nice choppy/lopey cam (at what point is a stall needed? I've read the 6L80 stall is surprisingly decent for a little bit)
-Upgraded push rods/springs/etc
-Headers
-Exhaust (size/catted or not/etc? will be axle dumped)
-Electric cutout (single vs dual?)
-L86 intake manifold/throttle body (ported or not?)
CAI
-Mayyyybe some gears (I miss that pin you in the seat torque &#128557
-Tune (mail vs shop tune)

I'm wanting to stay away from e85, as I'm sure I'll max out the current fuel pump and injectors, and upgrading that is just more money. It's a possibility down the road though.

Any and all input will be greatly appreciated!

Also, any suggestions for shops/tuners within a reasonable distance from the Beaumont, TX area please.

Thanks in advance!

Bgbldodge

Headers, exhaust, and a solid engine and transmission tune. Best bangs for your buck. And ask your tuner about changing up the stock converter lockup algorithm. 00pooterss has more details in one of his threads but basically the converter stays locked all the time and GM allows a finite amount of slippage and adjusts pressures constantly to keep it happy. This ends up burning up converters.

FFDP

iTrader: (2)

Put it this way, it will be impossible for a mail order tune to be right and you will be in a back and forth battle forever trying to get it right.

A in person tune on a dyno with someone with a ton of knowledge of the torque based computers is a must.

A real choppy camshaft is going to make noise and not really produce all the power you want, it will be a slug down low. Texas Speed and Brian Tooley racing all offer good "Stage 2" camshaft that should let you keep the stock converter. If the LSA is around 110-112 it still should have some cam lope at idle.

ZO6Ted

Unless you are doing it yourself a cam change will be pricey. Find a used pd blower to skip it all to go low 13's or better in your rig everything else stock. You'd also be torque happy again. Just mho.

00pooterSS

iTrader: (40)

Mine gets up for a 5.3, but it's no comparison to a 6.2

I've been over this scenario over and over in my head, with notes and calculators and the best thing to do is a 6.2 swap. You'll spend less and go faster. You can find used 6.2's for 2-3k, you'll spend that much on the 5.3 and still lose to a mostly stock 6.2

But if you want to make the 5.3 as fast as it can be you'll need a good tuner, heads cam 6.2 intake and throttle body, headers, catback from a 6.2 (it's 3.5") swap out the stock muffler on the 6.2 exhaust for a straight through muffler or buy a new aftermarket catback (I did the stock 6.2 catback with a magnaflow) and I would highly recommend e85 or 93 octane minimum. I'd run a 3200 or higher stall with sticky tires too.

Or could just bolt on a blower and headers/exhaust too.

As for cams, texas speed has a good selection for your truck. I'd probably go stage 3 or 4 with a 3200-3400 ish stall. But I still think the 6.2 with just a mild cam would still beat the heads cam stalled 5.3, possibly beat it with just a 6.2 swap alone with bolt ons. And then you can build on the 6.2 more as time goes on.. there's several ways to do this all up to you

00pooterSS

iTrader: (40)

Truck on the left is intake tune and headers regular cab short bed 5.3
Truck on the right is intake and tune 6.2 crew cab 4wd

4wd not used on this run

Both have 3.42 gears and both have 6 speed transmissions


This is why I vote just going to a 6.2 and modding it instead. Watch the 6.2 kill the much lighter and more modded 5.3

biggness

I appreciate the input, fellars.

If I were to go the 6.2 route, what all would I need to complete the swap?

Does it have to be the same year model?

Is a new ECU needed?

Flexplate?

Any suggestions on where to get a long block?

Again, any and all information will be greatly appreciated!

Bgbldodge

Needs to be same generation. Direct bolt in swap. Update the ecm with a 6.2 file and your done.

FFDP

iTrader: (2)

Find a 2017-2018 engine for the swap. There is a difference in the high pressure fuel pump connectors on the earlier engines.

biggness

Awesome. Many thanks.

Where are some good online places to look for one, in addition to local auto salvages? A quick eBay search had them priced a fair bit out of my price point.

And no need for a different flexplate?