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Old 08-30-2017, 01:29 PM   #1
Kudzupatch
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LS swap vs TBI replacement

Considering an LS swap for my 2wd lowered Suburban. Background is I drive it regularly, not quite a daily driver but close. Occasionally tow light weight trailer with a few hundred lbs on it. But I am rebuilding an wooden runabout so will be towing 2,500# +/- in a year or so.

Like everyone I want more power, better performance but still talking mild street engine with the power range in the lower RPM's. Mainly looking for more tourque than HP here. Power to tow and enough power to pass the slow pokes and not wonder if you made a mistake pulling out with the stock low HP engine!

LS swap would require me to buy a used engine, harness and computer to keep it in my price range. More work involved with the swap obviously and more time involved.

Other option is a 350/355 crate motor with Vortec Heads and using the TBI. I would prefer a 383 but they add about a $1,000 to the cost. Crate motor has warranty and is pretty much just bolt in. Will require computer tuning.

Assuming both cost being similar I was very much into the LS swap but the more I look at it from a practical standpoint I can't really see any advantage to the LS. Sure you get a new more modern engine but lots of extra work and as far as I see in my case, not a lot of advantages.

Am I missing something?
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Old 08-30-2017, 06:52 PM   #2
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Re: LS swap vs TBI replacement

I have towed with both a 5.3 and a TBI 350. The 5.3 did fine but it likes to rev to make the power. Choices given, I think a 350hp 350 will make better torque down low than a 350hp LS. My 7.4 is TBI and it is rock solid.
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Old 08-31-2017, 10:42 PM   #3
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Re: LS swap vs TBI replacement

Im sorry but tbi injection is just terrible. I would say a carb is better in every way than a crappy tbi. Maybe other than cold starting?

I'm putting an LS in my truck, but if you didnt want to do that, there is always lt1 engines as an option? Still keeps most basic 350 stuff but a much better injection system.
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Old 09-01-2017, 09:04 AM   #4
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Re: LS swap vs TBI replacement

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Originally Posted by indymachinist View Post
Im sorry but tbi injection is just terrible..
Maybe, if you don't know how to tune one.
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Old 09-01-2017, 09:13 AM   #5
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Re: LS swap vs TBI replacement

The aftermarket TBI systems seem to get good reviews. I went port fuel with a homebrewed system based on a Holley Stealth Ram manifold.
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Old 09-01-2017, 09:39 AM   #6
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Re: LS swap vs TBI replacement

If you're looking for power low in the RPM range, I don't think you'll be very pleased with the LS platform. My Silverado towed my Jeep on a trailer fine but it was sitting high in the RPM range to keep speed on hills, the 5.3 in my C10 feels the same but it will never tow anything.

The Vortec 350 would be a great setup in my opinion as it still has the low end grunt that most like paired with redesigned heads and injection system. My parents had a 96 4wd Tahoe with the Vortec 350 and that thing towed and drove really nice.
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Old 09-01-2017, 10:13 AM   #7
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Re: LS swap vs TBI replacement

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If you're looking for power low in the RPM range, I don't think you'll be very pleased with the LS platform..
I am hearing almost identical comments from several people in different places. At first I doubted it but when you keep hearing the same things over and over there is obviously some truth to it. I won't be towing that much but I appreciate low end torque.

Pretty much decided to buy a new L31 Vortec. Seems to be the best buy for the dollars especially when you consider it is brand new and with a warranty and is basically just a bolt in install.

I have done a lot of reading and as hard as it is, I will leave it alone. Just bolt on good intake, headers, exhaust so not to limit its breathing and be done with it. If I see a need might get the larger Holley TBI bit not sure I will really need it. And of course tune it! Something to be said for simplicity and reliability.

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Old 09-01-2017, 10:28 AM   #8
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Re: LS swap vs TBI replacement

I think that's a good plan based on what you have said.
Couple years ago my buddy in NH (who owns a 1963 17 ft Century Resorter) asked me to look for a full size blazer (1992-1995) here in Cali so he could tow his boat. After searching for a year I found a truck that had a new motor installed (running TBI) with headers, new radiator, AC,etc....Purchased it for $4,000 and had it shipped back east. He was thrilled, especially with the power and the fact the truck had zero rust. He did have the TBI unit rebuilt.
I can tell you (cause I rode along) his motor had zero problems pulling that Century 100 miles to Lake Winnipesaukee this summer for the boat show, where he took 1st place in under 22 ft post war utility class. Pulling out after the show on the steep launch ramp was easy.

Let us know how the L31 Vortec works out. Also, post some pics of your boat.
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Old 09-01-2017, 12:51 PM   #9
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Re: LS swap vs TBI replacement

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Also, post some pics of your boat.
It's in pieces now, about the turn the corner and start putting wood back in instead of just taking it out.

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Old 09-01-2017, 01:43 PM   #10
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Re: LS swap vs TBI replacement

Awesome to see this work being done. I looked over your albums - great job too with the photos man. You have a great eye for composition. Best wishes on the boat. Love the wooden boats.
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Old 09-01-2017, 02:29 PM   #11
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Re: LS swap vs TBI replacement

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Originally Posted by indymachinist View Post
Im sorry but tbi injection is just terrible. I would say a carb is better in every way than a crappy tbi. Maybe other than cold starting?
Carb is better in every way? A carb can self adjust for temperature and altitude? A carb can self-adjust for bolt-on mods (exhaust upgrades, etc...)? Please regale us with your tales of every way that a carburetor is better than a TBI setup.
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Old 09-01-2017, 02:37 PM   #12
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Re: LS swap vs TBI replacement

I noticed a couple of posts about a LS not having low end power.....well I'd have to disagree to that...my LS swapped 1 ton will boil all 4 tires thru the first 3 gears...I regularly pull a 9500 lb gross loaded trailer..and pulls it with ease..itll even smoke tires with that trailer behind it in 1st gear..I agree with one thing though...it'd be a lot easier sticking with what you've already got..but I'm firmly convinced with the LS being the best choice...is it the only choice..no.. but i think its the best choice.. (power, gas mileage, longevity).I didnt use to be but I'm a LS convert now..everyone's entitled to their opinion..
homemade87 is in g-ville as well..you should talk to him...I'm about a hour away from g-ville

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Old 09-01-2017, 05:00 PM   #13
Kudzupatch
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Re: LS swap vs TBI replacement

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...my LS swapped 1 ton will boil all 4 tires thru the first 3 gears...
A stock LS? Come on. That is what this was about, not a modified engine.
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Old 09-01-2017, 06:33 PM   #14
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Re: LS swap vs TBI replacement

bone stock...except for headers...it is a 6.0 but its stock..dynoed 299.3 rwhp and 345.8 rwtq..(nothing to sneeze at)
a burbs a big heavy vehicle so hard to compare...but you should take a ride in a half ton pickup with a LS in it before you pass judgement..
I've gotten more than a few peoples attention in my 1 ton..they just have no idea how hard itll take off...I'm running a nv4500 and 4.10s in it
like I stated above though...everbodys got a opinion on the LS swap...I'm just trying to clear the air or muddy the water...which ever way you look at it...if you were comparing LS to big block or diesel I could see a good arguement..but not when comparing LS to small block ..

Last edited by mongocanfly; 09-01-2017 at 06:54 PM.
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Old 09-01-2017, 07:50 PM   #15
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Re: LS swap vs TBI replacement

My LS is a 2005 4.8, stock it has 285hp, with a tune and headers, somewhere around 315 ish HP. With the 4l60e and 3.73's, it pulls my 2k Lb trailer just fine.
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Old 09-03-2017, 11:36 PM   #16
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Re: LS swap vs TBI replacement

Just one more old geezer's opinion.... I bought a new '02 Sierra 1500hd .. 6.0, 3.73 gear, 4L80E.... 10,300lb. towing capacity. Still have it 15yrs. & 200,000mi later, been a great truck, but i'ts not magic. It's thirsty, never given 15mpg empty and towing heavy and too fast I've got as little as 7mpg. It replaced a '92 G30 passenger van, 5.7, T.B.I., 3.73 gear, 4L80E trans. I towed a lot with it too and I think it had more low end ballz. I know it ran a little cheaper. Just for me I wouldn't go to the expense and work to do an LS swap for towing. Just for fun I would like a STRONG LS/6spd. combo in my short/step GMC or maybe the 2wd Blazer. NAH, I like the BB/5spd. in the Blazer.
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