Anyone have a LS swapped 3+3?

[KnockingDiesel]

Looking for insight on LS swapped heavy trucks. I intend to use my 3+3 C30 Dually as a cruiser and going out of town mostly, with some occasional towing like a 6x10 enclosed trailer with my motorcycles. I also would like to be able to pull heavy trailers, shorter distances as I work on RVs for a living. I’d like to hear real world experiences with 5.3/6.0/6.2 in heavier trucks.

I really want to LT L8T swap and 6L90 but the ls 6.0 6l90 seems “easier” as LS stuff is more readily available than LT and other options like cruise control, tow/haul mode, manual mode, etc. have been worked out.

I don’t really want a diesel or manual. I have a powerstroke but I’d like to build my square body as a back up.

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[codfish]

Check out Vice Grip Garage if you havent already on YouTube

He did that swap on the same truck. Just search Cat Crew Cab I think it’s called.Great show. I think a few episodes cover the swap.

Codfish

 

[KnockingDiesel]

Check out Vice Grip Garage if you havent already on YouTube

He did that swap on the same truck. Just search Cat Crew Cab I think it’s called.Great show. I think a few episodes cover the swap.

Codfish

Yeah I watch it all the time. His is 5.3 but I’m not sure how the power of it moves a 7500 pound truck since min is drw and I’m converting to 4x4. I’d also like to tow.

On a side note I’ve watched lots of YouTubers (including VGG) report many failures of Holley Sniper and EFI systems. That’s why I want to keep all stock GM components.

I’d really like L8T but seems cruise control and manual mode aren’t available with the swap.

The L96 6l90E would be able to have cruise control, manual shifting and tow/haul mode.

 

[CalSgt]

I wonder if the Dakota Digital cruise control unit would work on that set up….

 

[GTX63]

On a side note I’ve watched lots of YouTubers (including VGG) report many failures of Holley Sniper and EFI systems. That’s why I want to keep all stock GM components.

Yes, many of the buyers for those systems are looking for the reliability of late model injection. The problem is, and maybe it is due to marketing, is that they are generally not bolt on and walk away set ups.
I have known several guys who tired of the 6 pumps and goose the gas for 2 minutes carb owners who went with sniper systems and were not happy.
As one put it, "I used to spend about 20 minutes every few weeks under the hood, tinkering with my quadrajet; now I'm spending 20 minutes every few weeks under the hood tinkering with my sniper, only now I spent $1800 to do the same thing, and that was after the fight getting it set up."
The technology is there, and I believe it will get better, just sayin.

 

[TotalyHucked]

The L8T is just too new, swap guys haven't figured them out yet, cruise and manual shift will come with time. The best resource for swap info that I've found is the LS Swapped Squarebody GM Trucks page on Facebook. The page is run by Scotty Baccus that owns Tejas Steelworks and makes the swap mounts/shrouds/etc, there's a great Files section with all kinds of info on engines, cams, wiring, fuel system, gauges, etc. There's a basic "Swap Guide" in there as well. I used that alot when doing my truck.

For a heavy 3+3 dually that you're converting to 4x4, I would certainly lean toward a 6.0 or 6.2. If the budget is there, I'd probably grab the cheapest 6.0 I could find and do a 416 stroker build for maximum torque.

 

[Old77]

IF it was me, I'd use the 6.0 or 6.2. I just don't think the 5.3 has the torque to move the 3+3 dually down the road real well. My dually is pretty low miles so I've got years before I have to worry about engine swaps but when the time does come I'll be going the 6.2 route.

Just my $.02 cents

On a side note I’ve watched lots of YouTubers (including VGG) report many failures of Holley Sniper and EFI systems. That’s why I want to keep all stock GM components.

Down side is using stock oem fuel injection on that kind of swap is pretty painful. So you need to use Holley, Halltech, MSD,..... whatever. Holley did just come out with Holley Sniper 2 that is SUPPOSED to be more "plug n play"

 

[SquareRoot]

I'm glad to see that others are finally realizing that the Holley Sniper is one great big ole POS like I have been saying for years. I have posted about my experience with it so I'll leave it at that. On the other hand, I went back to Edelbrock Pro Flo, a true port EFI that uses 100% GM parts except for the ECU. I have been extremely happy with it and had zero issues. Not to derail the topic but I, and others I know, have had similar experience with FiTech. It just seems TBI and the concept of putting the electronics on top of the engine was not the best idea.

 

[KnockingDiesel]

I wonder if the Dakota Digital cruise control unit would work on that set up….

From what I’m seeing, it’s insanely expensive to tune and add functions to. Spear tech mods the harness and can tune the ECM/TCM for only $3,950 plus S&H. The L8T/6L90 are $10k engine, trans, harness and ECM/TCM. It’s still not bad considering the drivetrains have under 20 miles and a GM Connect and Cruise L8T/6L90 is $19k. The LT stuff requires a $500-$700 license fee to tune the ECM alone.

But the L96 6.0/6L90E is not only cheaper but WAY easier to tune and modify. Plus it’s proven platform for reliability.

L8T is about $16k installed 401hp 460tq

L96 is about $9k installed 360hp 380tq

I’m trying to figure out if the extra power is needed. I’ve never driven a 6.0 crew cab dually. Stats are similar to the smog 454 in it.

Im still considering buying a vortec 7400/4l80e to swap in.

My goals are adequate power, OEM multi port fuel injection and overdrive.

 

[Old77]

Im still considering buying a vortec 7400/4l80e to swap in.

My 91 has the stock 454 and 4L80e and it's got plenty of power and giddy up, honestly. It's another reason why I'm not in a hurry to swap until it's already used up and tired (only has 87k miles on it currently). So the vortec would probably more than sufficient especially if you don't have to spend $10k or more to accomplish it like the other options. That's spendy

 

[KnockingDiesel]

I'm glad to see that others are finally realizing that the Holley Sniper is one great big ole POS like I have been saying for years. I have posted about my experience with it so I'll leave it at that. On the other hand, I went back to Edelbrock Pro Flo, a true port EFI that uses 100% GM parts except for the ECU. I have been extremely happy with it and had zero issues. Not to derail the topic but I, and others I know, have had similar experience with FiTech. It just seems TBI and the concept of putting the electronics on top of the engine was not the best idea.

Every one I see installed is problematic, Vice Grip Garage left his cat farm crew cab in a parking lot during power tour couldn’t get the trans to shift out of 2nd with the Holley setup and has had multiple issues.

My main goals for this truck is reliability. I’d like to drive to 1500 mi No problem, at 75mph getting 12-14 mpg, with A/C on and cruise control.

I’m basically willing to build a new truck. It’ll be converted to 4wd in the next few months. Once that’s done I’m removing the drivetrain to sell off. The 454/th400 is decent running.

At which point I’m ready to start building/installing the new drivetrain. I am selling a few toys/cars I don’t use and will be able to dump it all into this truck. The bodywork/paint is the easiest part for me I can get everything done under $3k. Interior I can do for another $3k. My budget will be $15k-$17k initially but may be able to add more by selling off more unused vehicles (I have 11).

 

[KnockingDiesel]

My 91 has the stock 454 and 4L80e and it's got plenty of power and giddy up, honestly. It's another reason why I'm not in a hurry to swap until it's already used up and tired (only has 87k miles on it currently). So the vortec would probably more than sufficient especially if you don't have to spend $10k or more to accomplish it like the other options. That's spendy

What’s your highway fuel economy like? I have had a few 454 carb trucks that pulled decent but mpg was 6 to 9 empty highway.

I have the opportunity to get a 96 2500 suburban for $2500, rebuild of the 454 is $2.5-$3k and 4l80e rebuild is around $1.5k. $7k for a new drivetrain is pretty reasonable to me and it all bolts in.

 

[KnockingDiesel]

I'm glad to see that others are finally realizing that the Holley Sniper is one great big ole POS like I have been saying for years. I have posted about my experience with it so I'll leave it at that. On the other hand, I went back to Edelbrock Pro Flo, a true port EFI that uses 100% GM parts except for the ECU. I have been extremely happy with it and had zero issues. Not to derail the topic but I, and others I know, have had similar experience with FiTech. It just seems TBI and the concept of putting the electronics on top of the engine was not the best idea.

What’s pro-flo setup in? What fuel economy like?

 

[Old77]

What’s your highway fuel economy like? I have had a few 454 carb trucks that pulled decent but mpg was 6 to 9 empty highway.

I have the opportunity to get a 96 2500 suburban for $2500, rebuild of the 454 is $2.5-$3k and 4l80e rebuild is around $1.5k. $7k for a new drivetrain is pretty reasonable to me and it all bolts in.

About 13 mpg so not bad. Being TBI and having that overdrive makes a world of difference.

 

[SquareRoot]

What’s pro-flo setup in? What fuel economy like?

85 K20. 1 ton axles, Nv4500, 350, Vortec heads. 15-16 mpg