LS1 or traditional SBC

[Prostreet 72]

I need advise. I have a line on a 6.0L LS1 engine. The price is right. I would make the switch to a carb if I go this way. Can anyone tell me what I need to get with the engine to make it work for me. I will be using a TH350 trans.

Also, can anyone tell me the pros and cons of making the switch? I can build a bullet proof big inch big block, but these new fangled things are just that, new fangled things to me.

Chris

P.S.

This is going in the "Green Monster" build.

[texanidiot25]

The LS motors are a pretty simple motor to deal with once you decide to go with a carb and get rid off all the sensors need to run the fuel injection.

I'd go with a Carb'd LS1. Just about 400 hp right out of the box and the odd-ball carb'd late model motor.

[americanmusc1e]

5.7L LS1 or 6.0L LS2 or LQ4

which one are you talking about
i'm thinking about doing a LQ4 swap into my truck, the motor and tranny together go for about $1500

an LS1 or LS2 and tranny will cost you around $5000 easy

the reason i am going with an LS series is they take more HP on factory cast bottom ends although speed parts are more expensive for them

genIII smallblock (LQ series iron truck motors) cast bottom ends can handle about 700HP on stock bottom end without too much trouble

genI smallblocks (350 etc..)will take about 500HP on a stock cast bottom end

[Kid]

I'm not sure for your reasoning for eliminating the fuel injection/ computer control of the motor, but I will provide my personal experience & opinion. After putting a 5.3 with injection in my truck, i'll never go back to a carbed motor. Runs like a champ & I averaged just over 20MPG overall on the 08 "Power Tour".

[SactoJim]

If you go carb, you will also need a way to run the ignition....edelbrock and MSD have solutions.

Not too sure how the TH350 works....seems I read somewhere you may need a flexplate adapter or.....?

Sure someone will pipe in on this.

[71BB_LWB]

Not sure why you would want to get rid of the FI, but they are great motors, I only have a couple of miles on mine and I will never do a carb again, I love it.

[americanmusc1e]

Originally Posted by Kid

I'm not sure for your reasoning for eliminating the fuel injection/ computer control of the motor, but I will provide my personal experience & opinion. After putting a 5.3 with injection in my truck, i'll never go back to a carbed motor. Runs like a champ & I averaged just over 20MPG overall on the 08 "Power Tour".

any advice for someone like me wanting to do a LQ4 swap into my '70, what harness did you use???

[LEEVON]

Prostreet, the 6.0 is a great engine whether you stay FI or go carb. It's your choice, don't let anybody tell you different. FI offers great performance, tunability, driveability, and mpg. It's not that difficult, you just need somebody to do your tuning. Carb conversion is simple and effective.

For the carb conversion you will need:

MSD 6010 ignition controller and harness (people don't like the Edelbrock version because it's timing is not programmable and it has too much).

GMPP or Edelbrock (performer or victor jr) LSx intake for carb

6-7 psi / 110gph fuel pump and regulator

Flexplate adapter/spacer for TH350

Exhaust manifolds - S&P, Doug Thorley headers or 98 f-body stockers. I am going to use '04 GTO manifolds.

Check out the "conversions & hybrids" section on ls1tech.com.

[71BB_LWB]

Originally Posted by americanmusc1e

any advice for someone like me wanting to do a LQ4 swap into my '70, what harness did you use???

I know you asked americanmuscle but I will answer also. I used the factory harness, found all info I needed on LS1tech.com. You can buy a ready to go harness for $700+ or have a factory reworked by a pro for $450 (making it plug and play), or do it yourself like I did for cheap.
I bought HPTuners to do all my own tuning but there are lots of guys that can do it all for you.
Good luck either way!

[boostat4500]

If your going to switch to a carb, why bother with the 6.0L? I'm going to assume you all ready have a SBC in the truck? Why not just spend the money on improving it instead. Plus, it will cost you more to switch to a carb than just leaving it injected, even if you have to buy a harness and PCM seperately. Don't be scared of these motors. Once you get down to the basics, a motors a motor, whether from 2009 or 1960.
My .02
I can get you PCM pinouts if you decide to go that route and modify a stock harness, cheapest and pretty easy. Just let me know.

[texanidiot25]

Originally Posted by boostat4500

If your going to switch to a carb, why bother with the 6.0L? I'm going to assume you all ready have a SBC in the truck?

Because everything between the intake and out put shaft is better than an old school SBC. Even with a carb.

[Chevymann1968]

Well i was torn with the same thing then i read an article in a performance magazine and read about the motownLS it is an old school block adapted to run ls heads the best of both worlds!!!! But if you go with the 6.0 liter go with the lQ9 not the LQ4!!! The LQ9 has aluminum heads !!! This is the same motor i have in my Silverado SS The best time was a 14.3 at 94 mph So in know that ,that truck would run even better cause it isnt near the weight of my SS!!! Good luck with the choice!!!

Ernest B.

[boostat4500]

Actually, other than the very earliest LQ4's they both have aluminum heads. The difference between the LQ4 and LQ9 is the pistons. The LQ9 has flat tops and about a half point higher compression. Heads are identical.
And I agree that the motor is still better than a gen 1 even with a carb. I just don't understand dickin' with the swap if your not going to keep it's biggest advantage, the EFI.

[Chevymann1968]

Agreed!!!! Good call on the LQ9 and LQ4 I thought that the heads were different!!!!! Learn something new everyday!!!

[heavy71chevy]

Im planning on going the LS route with a carb...alot of people dont like the efi garbage IMHO so please dont flame me...For me its alot easier to adjust my holley double pumper with a screwdriver then cranking up my laptop to adjust anything.And the tested the carb vs efi on the LS familt of engines not to long ago...They held almost identicle numbers for power but it had more low end grunt to it with the carb and put out a good more torque with the gmpp manifold and a 750 holley atop the block

[Gray Ghost]

That's the point...with EFI you don't have to adjust a thing once the initial tune is done. That said I ain't here to talk anyone out of a carb. It took me the last ten years to come around to even thinking about a new gen motor. Now that I am here though, I'll NEVER pay to rebuild another gen 1 motor and I can't wait to ditch carbs forever.

With me it's all about getting 325-350horses WITHOUT stopping at every other gas station. Not toi mention starying effortlessly EVERY morning regardless of the temps outside.

Go with the LS motor, even if you insist on a carb. I doubt very seriously you'll be disappointed.

[heavy71chevy]

x2 gray..The way to swap the cam in the LS is pretty trick aswell and real easy

[Ackattack]

Gen III engines are great, and I've never had a problem with them. I've had 6 of them.

I think the big advantage of them is the fuel injection. You get all that power without hurting the wallet (gas $$$). In my corvette I have gotten 33mpg!!! And it ran a 12.18!!!

Plus, tuning with a laptop, you don't get your hands dirty

[Elephanthead]

Yeah, another vote for the fuel injection, also thumbs up on the motown ls1 old school block. If I was crapping out cash, I would build one of those.

[lowbucktruck]

If you want to drop an LS Gen III motor into your old truck, why not upgrade the transmission too? Why keep the old 3-speed Turbo 350 when you can get a newer auto tranny 4L60E or 4L80E that has overdrive and is designed to work with your LS engine. Makes more sense.

[Prostreet 72]

Originally Posted by lowbucktruck

If you want to drop an LS Gen III motor into your old truck, why not upgrade the transmission too? Why keep the old 3-speed Turbo 350 when you can get a newer auto tranny 4L60E or 4L80E that has overdrive and is designed to work with your LS engine. Makes more sense.

I hear you guys loud and clear, but here is the deal. I have 2 kids under the age of 3, two classic trucks, a house payment, daycare payments, street driven car payments etc. I would love to have the truck roll out with a LSX engine with a 6 speed manual trans in it, but I have to take baby steps with this truck. When I built the Prostreet truck, it was just my wife and I. Now a I have a couple more responsibilitys to take care of first before the truck. So that is the reason I need to go with the 350 trans. I have it on the floor of the garage. Later I would love to trade up to one of the later transmissions. But first I have to start with this one.

I will probably go with the carb over the fuel injection because I like carbs. I like how they look on these engines, and how they run on them. My trucks are not driven everyday. In fact, the black truck has not been wet, via a hose or rain drop in three years. So fuel economy is not my primary goal. I would just like to step up to something new. Learn something new for the future.From what I have been told by some builders, the stock LS1 with a carb swap will make 375-390hp out of the box. To take my tired old 350 andrebuild it to the same hp, I will spend more than I am on this new engine. Right now I can't expose my engine source, but after it is on my garage floor, I'll give you all his name and phone number.

This engine is coming with a spun bearing. Thus the low price. I still can't believe it myself. There are many, many more where this one is coming from. I will let you in in the source later.

I appreciate all of the help and guidance with my LS1 swap. You guys are the experts, having been there already. I may not go in the exact direction you went in, but still the same require your help with my swap.


Thanks a ton!

Chris

[67_C-30]

I'm still up in the air with this swap. There's no doubt that the LS engines are technologically better than the Gen I engine. With that being said, dollar for dollar, the old small block is still faster. (meaning starting with nothing and having to build a 10 sec car that runs on motor. That can be done cheaper with a Gen I). If I were going to swap one in a driver, I would definitely go with EFI. To me, that's they're biggest advantage. Having the power they have with the MPG they get. Putting a 750 DP on one is going to put it back to bad MPG and if I were not concerned with MPG and building a hot rod, I'd still go Gen I.

I just went through this dilemma with the engine I'm building for my red '69. I thought hard about an LS swap, but I ended up going with a .030" over 350 with Vortec heads mainly just because I already had the stuff. Being that I build my own engines, I am going to have less than $1000 in everything. I am building a carb'd version of the GMPP Ram Jet 350. I bought the same hyd roller they use it that engine, my compression ratio is about the same, and it makes 350HP and 400 ft lb TQ, which is fine for what I want to use it for. I'm not building a hot rod, I just want a fairly stout daily driver. I have a rebuilt non emissions 750 cfm Q-jet and after a just a little tinkering it cranks with 1 pump in the morning no matter how cold it is. The well worn 350 that is in the truck now gets 16 MPG with that carb with a TH350 and 3.08's. I'm putting in a 200-4R when I do the engine swap, so I'm confident I'll be close to 20 MPG with OD the tranny and fresh engine. I priced 5.3's and LS1's with 4L60E's and with mounts, exhaust, and all the wiring to put it in my truck, and I just couldn't justify spending that much more money for such a small gain in MPG.

As the prices come down, I am going to do this swap at some point. Like I said before, this is in no way a bash on LS engines. They are great. It just wasn't cost effective for me at this time. I hope I can put one in my 2WD Blazer later on. I will definitely be going with EFI if I do.

[67_C-30]

Originally Posted by Prostreet 72

I hear you guys loud and clear, but here is the deal. I have 2 kids under the age of 3, two classic trucks, a house payment, daycare payments, street driven car payments etc. I would love to have the truck roll out with a LSX engine with a 6 speed manual trans in it, but I have to take baby steps with this truck. When I built the Prostreet truck, it was just my wife and I. Now a I have a couple more responsibilitys to take care of first before the truck. So that is the reason I need to go with the 350 trans. I have it on the floor of the garage. Later I would love to trade up to one of the later transmissions. But first I have to start with this one.

I will probably go with the carb over the fuel injection because I like carbs. I like how they look on these engines, and how they run on them. My trucks are not driven everyday. In fact, the black truck has not been wet, via a hose or rain drop in three years. So fuel economy is not my primary goal. I would just like to step up to something new. Learn something new for the future.From what I have been told by some builders, the stock LS1 with a carb swap will make 375-390hp out of the box. To take my tired old 350 andrebuild it to the same hp, I will spend more than I am on this new engine. Right now I can't expose my engine source, but after it is on my garage floor, I'll give you all his name and phone number.

This engine is coming with a spun bearing. Thus the low price. I still can't believe it myself. There are many, many more where this one is coming from. I will let you in in the source later.

I appreciate all of the help and guidance with my LS1 swap. You guys are the experts, having been there already. I may not go in the exact direction you went in, but still the same require your help with my swap.


Thanks a ton!

Chris

I was posted while you were. I totally understand the kids and bills thing. If you go with the LS1 now you can always upgrade to OD and EFI later. If you getting a great deal, I say go for it. Most people who have them around here are way too proud of them.

[67_C-30]

When you get your engine, please put in line for the PM list of your source. I'd love to buy one that just needed a crank or something. I wanna tear into to one anyway!

[boostat4500]

Prosteert 72: I hear ya on the priorities change due to kids, etc. I'm there myself now with our first on the way. Because of that, I want to caution you now that you've given more details. Without giving away your source, can you tell us what exactley you are getting and for how much? Do you know the exact extent of the damage from the spun bearing? I'd be very afraid that your "great deal" turned into a nightmare.
Also, I understand the reasons of wanting a carb, but just be aware it is going to cost your more money to convert to a carb than to leave it injected, no matter what the motor comes with or without. Just trying to save you some frustrations/headaches.