Ls swap opinion

[3767]

As time has went by, I have noticed that it would seem more folks are going this route vs rebuilding there given engine. I have also noticed that some guys while doing their build thread, have been replacing a given engine with an ls model. Also that the engine they had in some cases, didnt have a problem while others were going to have to rebuild/ replace anyway. All this has lead me to ask what reason(s) any of you that have been down this path had? I'm sure some will say they were getting poor fuel mileage and now it's almost double. For others it just may have been they wanted to simply try this engine out. I wanted any and all feedback on not only any reason but now that its done how do you like the change? What are the cost involved? I like the idea of any benefit it has but just for the guys who havent done it and may be on the fence what are we in for? Better mileage?, longer service life of the engine? Etc..Thanks in advance for any feedback.

[Thealien]

When I did my 1972 4 X 4 Jimmy the camshaft lobes got ruined on my stock 350. After pricing out crate motors etc and I had hot start issues I purchased a 5 mile 2005 5.3 from spaulding auto for about $2500 delivered. With that being said I ended up $10,000 into the swap. Do I have any regrets, hell NO!

Going from about 200 horse power to 325 wasn't bad either. Could sit for months and start at the turn of the key. Cruise for hours while getting 15-20 MPG. I had planned on doing an LS swap on my new to me 1972 two wheel drive but I have rust issues to deal with first (or selling).

[truckster]

I own 2 GM trucks that are one year apart; one has a 5.7 Vortec and the other a 5.3 LS. There's not an appreciable difference in fuel mileage between the two. Both have 3.73 rear gears. They weigh almost exactly the same. I haven't timed them, but the Vortec seems to accelerate better.

I did have to replace a distributor and fuel injection spider on the Vortec at about 130,000 miles.

Based on my experience with both engines, I built a 5.7 Vortec for my 72 Blazer. I put in a better cam, replaced the stock Vortec valve springs with stock springs from a 1st gen 350, and it's got HEI and a Quadrajet. I haven't quite gotten to where I can drive it, but it should put out around 330 horses and 400 lb-ft of torque.

[57taskforce]

Originally Posted by truckster

I own 2 GM trucks that are one year apart; one has a 5.7 Vortec and the other a 5.3 LS. There's not an appreciable difference in fuel mileage between the two. Both have 3.73 rear gears. They weigh almost exactly the same. I haven't timed them, but the Vortec seems to accelerate better.

I did have to replace a distributor and fuel injection spider on the Vortec at about 130,000 miles.

Based on my experience with both engines, I built a 5.7 Vortec for my 72 Blazer. I put in a better cam, replaced the stock Vortec valve springs with stock springs from a 1st gen 350, and it's got HEI and a Quadrajet. I haven't quite gotten to where I can drive it, but it should put out around 330 horses and 400 lb-ft of torque.

That’s because the 5.3 has a ton more torque management programmed in than the vortec does. If that 5.3 was tuned it would blow the doors off a stock 5.7.
I’m working on the swap for my K20 for a few reasons. The LS platform is an incredibly reliable and capable engine family. Stock engines handle boost incredibly well. They make can make serious horsepower very well and still quite affordably. If anyone has ever wondered how durable these engines are read this:
https://www.hotrod.com/articles/hrdp...g-bang-theory/

The 6.0 going in my truck has only a cam and some bolt ons and should be 550hp+ at the crank and still completely streetable and will allow me to still use my K20 as a truck. In order to get that kind of power from the old small blocks you’d have to be pretty built with a lot cam which obviously isn’t ideal for my application at all. If power isn’t what one is after plenty ls truck motors have gone well past 300,000 miles. They are reliable and even with the ease of operating that come with efi they still easy to work on. These are just a few reasons I’m swapping mine.

[bigdog55]

I have rebuilt the top end of my 350 once since I've had it and need to do it again, I am tired of putting money into something that leaves me stranded. I am trying to rake up the money for a rebuilt 6.0. Hopefully it will run for a long time with better performance.

[chev-obsession]

The reasons why are different for everyone. Some common reasons to why someone go with an ls swap.... it’s the cool thing to do, makes for a fun project, the ls series is a modern engine and being more fuel efficient, starts on the first crank, don’t have to pump the carb before you start, they run just as good in 110 degrees as they do in -20 degrees no carb tuning issues, and they seem to never die... all goes with the modern amenities that we are used to now days.

I haven’t looked in a while so maybe they gone down but specifally remember if you wanted to buy aluminum heads for your SBC you were looking at dropping $1,000 for “cheap” ones. VS an LS comes with them standard.

Some people are able buy a wrecked vehicle, take what they need for the ls swap, do all of the work themselves and part the rest out and get the whole swap for free more or less. Others spend upwards of $10,000. Just depends on your taste and abilities.

Not slamming anyone either way, but those are some reasons why.

[fastpace]

Main reason I did it was just reliability and capability to daily drive the truck. For the cost of rebuilding a SBC you can be a full LS based setup and conversion parts. Having the sensors and controls keeping it running reliably. For me, it was really just those simple things, the same reason GM has evolved from the SBC to the LS and now the LT.

Can understand the other side which is the originality and vintage of driving a carbed SBC, but I wanted my truck for more than just going on cruises. I want to enjoy it and treat it like it's a new truck off the lot in terms of capabilities.

[Smoke 1969]

For me I had a bad 350 in my truck and a good friend of mine already did an LS swap so I decided that I was going to do it to, I just love it, turn key and start, I drove it for two years now and this winter I'm doing an off frame on it, it goes in next week to get the outer body painted, I better mention the motor is a 2011 6L out of a truck, I wanted an 6.2 out of a vet but they were not in my price range

[MDPotter]

I'm an LS fan for sure. It starts up every time, runs great, and is efficient. My 68 had a 307 (not the best SBC) when I bought it and it ran great, but it was pretty gutless and not good on fuel mileage and didn't like the cold. Now that I have a 6.0, it's a night and day difference and I would not go back.

We just bought a 69 and the previous owner had the 350 bored and stroked to 383, Edelbrock heads, roller rockers, Weiand intake, Holley carb, HEI ignition, and polished serp drive system. It's a fresh build and he spent about $10k on it. $10k will get you a low-mileage LS engine, rebuilt 4L80E, and all of the parts that go into an LS swap - radiator, fans, fuel tank, fuel pump, gauges, and a bunch of upgrades to the powertrain. You can spend all that money and have an engine with a good amount of HP and will start every time and get better mileage.

Like chev-obsession said, some guys are able to find wrecked donor vehicles and end up breaking even. Don't get your hopes up in being able to do this, but plan on buying an engine on eBay, doing a tuneup (replace plugs, wires, water pump, power steering pump, idler pulley, tensioner pulley, belt, etc.) and get a rebuilt 4L80E from LSX4U, and piece together the rest of the components.

[cebra]

I daily mine so SBC was costing me around $900 a month in gas and it ran like crap. I personally hate carbs and think they are stupid complex to try and tune. The LS is a wonderful engine, great gas mileage, good power, starts every time hot or cold, widely available. I feel much more comfortable working on it as the computer (generally) tells you exactly what is wrong, there is no guesswork involved or "feeling" to tune, the air/fuel ratio is either right or wrong. I have put 11K miles on it in 2.5 months now.

[ho70]

Well, I wasn't a LS swap fan. Loved the classic engines. Just rebuilt my 402 and......a LS is more reliable and fuel efficient and you don't stink like gas riding in your truck. I am building a swb 68 and it's getting a LS.

[tim_mc]

I have an '02 Z28 convertible w/LS1 (love it) and am a fan of LS swaps. However, since my 1st gen 350 SBC is running so well in my '67 C10, I'd have to find a heck of a deal on an LS to upgrade. Right now pumping the accelerator 5 times before hitting the key is "nostalgic", but maybe that will get old one day. When that happens, one future option for me is to just add fuel injection.

[truckster]

Originally Posted by tim_mc

I have an '02 Z28 convertible w/LS1 (love it) and am a fan of LS swaps. However, since my 1st gen 350 SBC is running so well in my '67 C10, I'd have to find a heck of a deal on an LS to upgrade. Right now pumping the accelerator 5 times before hitting the key is "nostalgic", but maybe that will get old one day. When that happens, one future option for me is to just add fuel injection.

Is your choke working?

[tim_mc]

Originally Posted by truckster

Is your choke working?

It has an Edelbrock 1405 w/manual choke not hooked up. I may get a cable for it, but in cool & warm weather it starts easily. It's just in freezing temps that it requires a few pumps. Once warm, it's good to go. Having no choke is another layer of anti-theft protection.

As for LS swaps, my neighbor is putting together a square body with an LS that he's rebuilt. He's done a great job so far and has offered his advice & support if I ever move forward on my own swap.

[CastIron]

As a professional auto technician, I would have an easier time than most doing a LS swap. But I didn't bother a few years ago when I replaced the engine in my C1500. I just installed a crate 350 and called it good. It starts and runs fine every time I need it to, regardless of the conditions. As little as I drive it, I haven't done anything but oil changes since then. I expect it will last me another 20 years with no problems.

[3767]

I just wanted to say thanks to all of u guys for your post. I hope that n the coming days more will chime n with their story. I know 4 some the weekend is the best time to post and for others its not. But I can say that from a money stand point if u build a gen 1 with say 400+ horse,give it fuel injection, u have at least the same if not more money in to it all than the ls swap.

[LS short box]

I'm a big LS fan. I've done over a dozen swaps for me and my car buddies. First almost about 15 years ago. Mostly small cammed and headers so the chassis tune was easy for the local tuner.
I typically buy the ecm and harness from one supplier. I like Howell and Speartech. I'm not an electrical guy so I'm not comfortable cutting down a stock harness.
So much aftermarket support now I think its the only way to go.

[Myself]

For a daily driver.....I think the LS is great. If it's a weekend warrior or show truck, I'm going for the old school carbed ground shaker!

[pilotXC]

I wanted to be able to keep up with traffic on the highway instead of screaming at 3500 rpm doing 60mph. Along with that came the other niceties of a more modern engine. Easy start up, no gas smell, reliability, durability, performance. Mine is night and day from the SBC 350 that was supposedly 300hp. I have a stock LQ4 and 4L80E and it will light up the tires when it shifts to 2nd gear if you're into the throttle. It also drives like a newer truck around town. I don't drive it much, but it's awesome to just jump in and go when I do. All that said, it was WAY more work than I was anticipating and would have done some things different if I did it again and had more time to dedicate to it. I also feel much more comfortable driving it on any trip if I was going to... Just finished it a few weeks ago, so still working out some kinks, but when it's done and I don't have to think about it, it will be great to have the classic look with modern performance and reliability.

[truckster]

Originally Posted by pilotXC

I wanted to be able to keep up with traffic on the highway instead of screaming at 3500 rpm doing 60mph. Along with that came the other niceties of a more modern engine. Easy start up, no gas smell, reliability, durability, performance. Mine is night and day from the SBC 350 that was supposedly 300hp. I have a stock LQ4 and 4L80E and it will light up the tires when it shifts to 2nd gear if you're into the throttle. It also drives like a newer truck around town. I don't drive it much, but it's awesome to just jump in and go when I do. All that said, it was WAY more work than I was anticipating and would have done some things different if I did it again and had more time to dedicate to it. I also feel much more comfortable driving it on any trip if I was going to... Just finished it a few weeks ago, so still working out some kinks, but when it's done and I don't have to think about it, it will be great to have the classic look with modern performance and reliability.

The RPM at any given speed is a function of gears (transmission and rear) and not of the engine.

A properly adjusted carb will be just as efficient as fuel injection. The advantage of fuel injection is that it makes the adjustments for you. I'm adding cats to mine to keep the exhaust clean. And as far as driving it anywhere, I went across the country with my Blazer long before I decided to replace the engine.

I get it, everyone wants what's new, but the advantages have to outweigh the costs for me, and I haven't seen that. Bottom line - do what makes you happy; it's your truck.

[pilotXC]

Originally Posted by truckster

The RPM at any given speed is a function of gears (transmission and rear) and not of the engine.

A properly adjusted carb will be just as efficient as fuel injection. The advantage of fuel injection is that it makes the adjustments for you. I'm adding cats to mine to keep the exhaust clean. And as far as driving it anywhere, I went across the country with my Blazer long before I decided to replace the engine.

I get it, everyone wants what's new, but the advantages have to outweigh the costs for me, and I haven't seen that. Bottom line - do what makes you happy; it's your truck.

I did... There's a reason not a single car is made with a carb anymore, and it's not simplicity and cost savings. I also don't own a tube TV anymore either.

I understand gearing and mentioned I also put in a 4L80E therefore adjusting the gearing. I didn't do an engine swap for better highway speed.

[truckster]

Originally Posted by pilotXC

I did...

Sorry, I intended that for the original poster.

[cebra]

Related to costs, there is a cost calculator on here for LS vs SBC. Mine will pay for itself in a year or so due to the high mileage I put on my truck (~30K a year), assuming nothing breaks with the LS and wouldn't have with the SBC.

[MidLifer]

It’s pretty much all been covered but I love my LQ4/4L80e setup. Love starting up in all weather, no more stalls from low vacuum, 6.5 seconds 0-60 (yeah a Tesla is faster but this is a 5000 lb truck!) and I can run regular from the pump and not worry about ethanol damage.

Swaps are fairly involved. For me, even as an electrical engineer the electrical part was the most daunting. But I went for a OEM harness instead of one of the packages. Had to build relays and an aux fuse box.

I paid $2300 for engine and trans and ended up around 5k all in.

[kipps]

My initial reason was a little different than others stated.

I was starting from a early TBI truck. It was increasingly troublesome, and something needed to happen. I was faced with several options.

#1, replace the TBI with a carburetor. The cheapest option, but it felt like a step backwards. Also, my flat-tappet engine core was likely having issues that even a carb swap wouldn't fix. To do this right, would mean learning how to tune and adjust my own carburetor. Not impossible by any means, but I'd be putting effort into learning an outdated system.

#2, Replace the TBI harness and fully learn the TBI system myself. Again, it seemed bad to be putting a lot of effort into learning an older system.

#3, Swap to an LS. definitely the most expensive option, but the effort put into understanding and tuning this system would be the most "future-proof" compared to other options.