When you reach a fork in the road, take it.

[Hipster]

And a 2800 stall converter

people underestimate the value of a decent converter. Had a Turbo-Action tight 10" in my old Challenger, drive around all day it behaves like a stocker, mash the go pedal and it would flash to 3.4k behind a stroked BB. People that build a 5-6k engine and back it up with $150 reman converter leave a ton of go-fast on the table. The right converter or a custom built one makes a world of difference.

 

[L31MaxExpress]

And low end torque.

Yep something the LS seriously lacks. I love leaving 5.3L trucks with loud obnoxious exhaust setups seeing tail lights in everything I drive. There is a lowered Tahoe in my area that sounds straight piped that has seen tailights of both the Van and the Pathfinder in the last month alone. The old 4.0L/5spd literally jumps out of the hole compared to a 5.3L Tahoe and it just gets worse when the all 4Lslippy goes to grab 2nd.

 

[L31MaxExpress]

That's part of it. All 2500 6.0l rigs should come standard with 4.10s.

The newer vans come with 3.42s in a 3500. Even with a 6L90E they could have used 4.10s.

 

[L31MaxExpress]

Swapping the 454 out for a 5.3 in my shitbox was the best thing I ever did. Drivability went up 10 fold, fuel mileage more than doubled, and the get up and go dramatically improved. My truck is just a cruiser, doesn’t really tow anything, and it for having fun. I don’t need big gas sucking power. I was considering going with a 6.0 but I found a 2005 truck with 158,000km that was smashed and got the whole thing for $1000. All I HAD to buy were mounts, fuel pump and made my own lines. Also reworked the harness myself. I used the e fans, pedal, tac module etc all from the donor.

But this is just my experience. Everyone else’s may differ

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I honestly do not know how. The 5.3L has to be one of the worst running engines I have ever driven next to the TBI 2.8L I had in a S15 Jimmy 4x4. I drove a square body suburban with a TBI 454 for a while and it was a very strong runner. With a TH400 and 3.73s it would get 15 mpg every tank in mixed driving. The 454 never felt like it was even flexing a muscle to move the thing. Granted it was an 80K mile truck when I bought it and I put 3" duals on it off the manifolds with a H-pipe.

 

[OutlawDrifter]

I honestly do not know how. The 5.3L has to be one of the worst running engines I have ever driven next to the TBI 2.8L I had in a S15 Jimmy 4x4. I drove a square body suburban with a TBI 454 for a while and it was a very strong runner. With a TH400 and 3.73s it would get 15 mpg every tank in mixed driving. The 454 never felt like it was even flexing a muscle to move the thing. Granted it was an 80K mile truck when I bought it and I put 3" duals on it off the manifolds with a H-pipe.

Worst running? I've never had an issue with how a 5.3 runs, and as stated earlier, I've put a fair share of miles on multiple rigs equipped with one. I would agree that 2.8 was anemic for sure.

15mpg mixed out of a 454 TBI Suburban????!!!!! Maybe if you dropped it out of an airplane and let it idle on the way down

 

[Sle-z_90]

I really appreciate everyone sharing their experience and opinions.. I'm about 90% decided that I want to go ls swap. Specifically, I'm planning to find a cheaper 4.8/5.3 to start with. I'll mate it to my 700r4 for now. Once its running, I'll deal with any other issues that are as of yet unknown. Then, I'll beef up the trans and rear axle. I'm thinking a 4l80 and 6 lug rear axel from a light duty c2500. I'm thinking a 4.56 ratio with a g80 locker if I can find it b/c 0-60 acceleration is my top priority. When I swap the rear axle, I'll swap out the front rotors for the 6 lug rotors and brake calipers. I'll also do wheels and tires at this time. At some point in all this, I'll do the NBS master cylinder upgrade. The next step will be either 2/4, 3/5. or 4/6 drop. Next, would be performance build, either turbo the 4.8/5.3 or build a 6.0. I'm leaning toward turbo the 4.8/5.3 if it is running good. That way, I would have the turbo in place already and could build a 6.0 with that in mind in the future. But also, if I'm happy with a turbo 4.8/5.3, then I can just enjoy it while it lasts. Last thing would be paint, although I havent really considered paint and body too much. I may change the body mounts when I do the drop as well.

 

[0xDEADBEEF]

I really appreciate everyone sharing their experience and opinions.. I'm about 90% decided that I want to go ls swap. Specifically, I'm planning to find a cheaper 4.8/5.3 to start with. I'll mate it to my 700r4 for now. Once its running, I'll deal with any other issues that are as of yet unknown. Then, I'll beef up the trans and rear axle. I'm thinking a 4l80 and 6 lug rear axel from a light duty c2500. I'm thinking a 4.56 ratio with a g80 locker if I can find it b/c 0-60 acceleration is my top priority. When I swap the rear axle, I'll swap out the front rotors for the 6 lug rotors and brake calipers. I'll also do wheels and tires at this time. At some point in all this, I'll do the NBS master cylinder upgrade. The next step will be either 2/4, 3/5. or 4/6 drop. Next, would be performance build, either turbo the 4.8/5.3 or build a 6.0. I'm leaning toward turbo the 4.8/5.3 if it is running good. That way, I would have the turbo in place already and could build a 6.0 with that in mind in the future. But also, if I'm happy with a turbo 4.8/5.3, then I can just enjoy it while it lasts. Last thing would be paint, although I havent really considered paint and body too much. I may change the body mounts when I do the drop as well.

You don't need all that extra weight. The 4l60 and 10 bolt are holding up fine so far behind the heads/cam 5.3.

 

[L31MaxExpress]

Worst running? I've never had an issue with how a 5.3 runs, and as stated earlier, I've put a fair share of miles on multiple rigs equipped with one. I would agree that 2.8 was anemic for sure.

15mpg mixed out of a 454 TBI Suburban????!!!!! Maybe if you dropped it out of an airplane and let it idle on the way down

The late Bruce Plecan "Grumpy" on TGO was getting 17 mpg out of an earlier 454 TBI that had 4.10s and 31" tall tires and 12-13 towing. The tuning in that Suburban had some ideas he had implemented on his truck. At light load we were targeting very low 02 switch points with a fair chunk of cruise timing. Made the engines run smooth and crisp.

 

[OutlawDrifter]

At some point in all this, I'll do the NBS master cylinder upgrade.

Skip this...its a downgrade. If you want better brakes, go hydroboost.

edit: For reference, I tried it on a '95 RCSB and it was garbage.

 

[Sle-z_90]

Skip this...its a downgrade. If you want better brakes, go hydroboost.

edit: For reference, I tried it on a '95 RCSB and it was garbage.

I'll look into more when I get to that part of the build. Thank you.