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#1 |
Registered User
Join Date: Mar 2014
Location: Atlanta GA
Posts: 94
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LS vs 383
I'm debating which one to do 383 or LS I will be driveing my truck every day so I'd like to get decent gas mileage. I will only be running a fan and alt no ac or other bull crap just an FYI there.
LS 327ci 327hp LS people I have a few questions. What is the difference between the numbers like ls1,2,3 so forth? Will it bolt up to my 350turbo automatic trans? (I may buy a new trans... What should I look at?) Will I need to change my gear ratio?( I'm buying a 5 lug axel off a guy thinking about makein it posi) How would my mpg be not playing with it? I will drive my truck not let it sit just for me to look at.. Should I get new harnes to be reworked? (Or do they put all new wires on?) Where do I take them to do so? How much does that cost? 383 310hp 385TQ What would my mpg be driveing it no playing? Wouldn't my wireing harness hook up the same? |
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#2 |
Registered User
Join Date: Aug 2012
Location: tucson,az
Posts: 274
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Re: LS vs 383
search is your friend, most of these have been answered time and time again. If mileage is your first priority the ls will make more power efficiently cube to cube.
I would think the 383 depending on build will be slightly stronger then a 5.3(325ci) but it will not be much. An LS will bolt up with an inexpensive adapter to any gm trans. but once again if mileage is your goal an overdrive trans is a must. Good luck and do some research on here there is lots of info with just the questions you asked. cheers bpatrol |
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#3 |
Registered User
Join Date: Feb 2008
Location: Tacoma Washington
Posts: 890
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Re: LS vs 383
I have been running big blocks for a long time, but I'm about 90% sure I will put an LS in my K10 when the 396 pukes or I get the time. The 5.3 in our Tahoe is great.
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I know a guy who's addicted to brake fluid. He says he can stop any time. 72 K10 396 75 Cj5 MPI 350 Chev 67 Chevelle 396, 4 speed 74 FXE 08 Tahoe |
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#4 |
Registered User
Join Date: Jan 2013
Location: San Antonio, TX
Posts: 733
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Re: LS vs 383
interested
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Figure out what you want--then figure out what you are willing to give up to get it. |
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#5 |
Registered User
Join Date: Oct 2007
Location: Houston, TX
Posts: 141
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Re: LS vs 383
Speaking as a person who has done the LS conversion I would first do a cost comparison on the two engine set ups. Doing research is the key here. I chose the LS1 for my build for the reliability of it.
A brief description of the LS motors can be read here but it is not all inclusive: http://www.ssrfanatic.com/forum/f5/d...nations-27127/ If you are looking for better mileage I would opt for a newer transmission ( like a 4L60E). Youj dont necessarily need to change the gear ratio. I'm running a 3:73 gear in mine with a 5 lug setup. Gas mileage wise I get about 22 mpg. With a LS engine I would recommend getting a new harness. Doing so will elimenate a lot of clutter not to mention time and frustration due to the fact you don't know the history (wire breaks, etc.). Several shops sell new harness online and pricing varies. Here is my set up: ![]() Good luck!! |
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#6 |
the boat guy
Join Date: Jul 2007
Location: springfield mo
Posts: 2,339
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Re: LS vs 383
Gm doesn't make a 327cid ls based engine. The 5.3L is the closest at around 325 cid.
All ls engines have an aluminum block and are quite pricey when compared to the Ls based truck engines that all have iron blocks. All ls based engines will bolt to any transmission as any other sbc or bbc. The cost of bulding a comparable hp sbc is about the same if not more than swapping a junkyard truck engine. Then if you want more power the sbc will possibly need to be rebuilt for n20 or forced induction while the ls based engine might need bigger injectors, fuel pump, and a tune.
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67, swb, fleet, tach, throttle, 5.3, 4l60e, 3.73's, fuel cell, 5 lug, p.d.b., 4-6 drop. great little truck 66, stevens drag/ski 18' silouette, 350, 2.02 doublehump heads. comp extreme marine 278 cam, vette 7 fin valve covers, old polished edelbrock intake, velvetdrive, casale v-drive, adj cavitation plate. 28, model a rpu project, |
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#7 |
Registered User
Join Date: Mar 2014
Location: Atlanta GA
Posts: 94
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Re: LS vs 383
it must be a typo then I have a picture right here Chevrolet performance #809-19244096 LS 327ci Engine 327hp 347TQ.
I will build later as for right now im getting a crate. I've price checked 3,600 for 383 and 4,200 for the LS. that does look pretty sweet 383 cast iron block 310hp 385TQ.. so far the stroker seems better and more TQ and I could use spray later on I will get an ls in another project I plan on having a few ![]() I looked up that 4L60E on monster transmition and that aint bad for a new better trans 1,430 so ill end up getting that to go with the 383 |
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#8 |
Registered User
Join Date: Feb 2011
Location: Modesto, CA
Posts: 2,188
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Re: LS vs 383
There really shouldn't be too much of a debate if gas mileage is a question. What will hurt mileage is the 3 speed auto. A 4 speed auto would keep rpms low. The ls1 can be built to push f - bodies into low 10 second quarters so there's no doubt it can be built plenty powerful enough. It just has refined head design and fuel injection to bump mpg's. Either motor would be cool.
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#9 |
Registered User
Join Date: Jan 2014
Location: Houston,TX
Posts: 258
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Re: LS vs 383
Not a typo that is a LS327 5.3
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#10 | |
Registered User
Join Date: Nov 2000
Location: Huntsville Ontario Canada
Posts: 4,052
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Re: LS vs 383
Quote:
![]() I have only ever owned carbed and tbi engines. Just bought a 2005 Tahoe with a 5.3. I love it I would be great to have that engine over the 383 I had in my work truck any day.
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1968 Suburban numbers matching all original truck now equipped with 6.0/4L80 on Accuair http://67-72chevytrucks.com/vboard/s...d.php?t=625017 1967 C/20 6.0/4L80 Roofing Truck 1990 V2500 Suburban "Plow Truck" 2005 TAHOE DD |
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#11 |
Registered User
Join Date: Aug 2012
Location: tucson,az
Posts: 274
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Re: LS vs 383
the ls327 designation is just marketing people know 327's so they market them as such. Its no big deal and not worth debating. the reality is its a 325 close enough for me.
ls based engines are aluminum and iron. Iron being less expensive without a real drop in performance once you change certain parts. One Big benefit to ls based engines is they run wayyyy cooler temp wise If you are worried about all the wires just carb it. very simple almost the same as wiring a sbc. and still good mileage and power depending on carb. (600 electric choke) would be great. good luck |
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#12 |
Old member
Join Date: Jan 2002
Location: Liberty, & Garden City S.C. , U.S.
Posts: 19,936
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Hands down LS motor.
A stock 6.0 LQ4 is rated 325 HP at the fly wheel stock! A lsx LQ9 is rated at 345HP at the fly wheel stock! Plus you will get 16-20 MPG with the 4l80e are 4l60 are if you go big get the new 6 speed auto and get even better MPG. No 383 is going to get close to the numbers of the LS engines and the money is doubled on the 383 to get the HP out of it. I just finished my 6.0 LQ4 swap with 4l80e and it's dyno'd at 280 HP at the rear wheels not the crank. 305 Torque at the rear wheels. It's all stock except for the long tube headers. + it's getting 17MPG. ![]() ![]()
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1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 ![]() Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. |
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#13 | |
Registered User
Join Date: Oct 2012
Location: Detroit
Posts: 748
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Re: LS vs 383
Quote:
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#14 |
Registered User
Join Date: Aug 2012
Location: tucson,az
Posts: 274
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Re: LS vs 383
its okay I don't take it as an attack on me, we all arel here to learn
Fact is a carbed ls will make more peak hp and tq then a fi engine. fi is better everywhere else. if you put a proper size carb with vacuum secondaries and an electric choke with a dual plane intake they get great gas mileage. I have a 67 Camaro that has a 6.0 carbed ls motor with a quick fuel carb and gets 25 mpg with a 6 speed and 3.73 rear end my friend has the same set up but f.i. and gets about the same and both cars are 440 plus at the wheels. These motors just breathe better and make power easier, carbed or fuel injection. Lastly some people still want the cool look of a carbed motor. with a msd box firing the coils everything else is exactly like a small block so much easier to wire and no computer needed. Sometimes people are just starting out with a block and need to buy everything god speed and good luck |
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#15 |
Registered User
Join Date: Jan 2014
Location: Houston,TX
Posts: 258
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Re: LS vs 383
Fuel mileage yes but where do you get that you loose hp/torque?
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#16 | |
Registered User
Join Date: Oct 2012
Location: Detroit
Posts: 748
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Re: LS vs 383
Quote:
All I am saying is other than for price (if starting with a base engine, and still not a big cost different with the amount of parts floating around the junkyards), the fear of electronics or the looking "old school" I guarantee dollar for dollar i can go faster with EFI. The only advantage a carb has over multiport fuel injection is the atomization of gas due to its pressure differential. If we are talking prostock motors I agree with bpatrol that a carb motor makes more peak power, but we're not. The cylinder to cylinder fuel distribution of efi blows a carb out of the water. Not to mention I can make on the fly adjustments with a laptop ![]() Remember in the end it is about combustion efficiency! |
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#17 | |||||
Registered User
Join Date: Apr 2012
Location: Covington, GA
Posts: 386
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Re: LS vs 383
Quote:
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If you're thinking transmission swap, you can use the 4L60E or 4L80E that came with the engine, and you'll get an extra gear that will help with mileage. Quote:
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Matt Cramer 1972 Chevy C10 - 4.8 swap, long bed, and maybe one dent free body panel somewhere - SOLD 4.8 LS build thread |
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#18 |
Registered User
Join Date: Jul 2006
Location: Columbia, SC
Posts: 410
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Re: LS vs 383
how much is the 4.8/5.3 LS motors worth to get the motor, trans, and computer all together? you all have me interested now in the swap for my new '68
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1968 Chevy C10 swb fleetside ![]() 2005 Chevy Silverado crew cab (SS) 1977 Goldwing cafe racer 1977 Chevy nova (first car/ first love) ![]() |
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#19 |
Registered User
Join Date: Oct 2012
Location: Detroit
Posts: 748
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Re: LS vs 383
Depends on the trans. A 4.8/5.3l complete with trans in my area around 1000-1500.
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#20 |
Registered User
Join Date: Jun 2010
Location: Upland Ca
Posts: 4,143
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Re: LS vs 383
I'm on my 3rd 383. To get the rear wheel HP & Torque in a useable, streetable RPM band and the manners of an LS it cost about $6k (carb to pan) and you still need the transmission to handle that power, headers, etc. A complete LS pull out (engine, trans, all drive accessories, ecu, harness, etc) is about $2k. Another $2k for all the extras like mounts, headers, harness rework, tune, dyno, efans, upgraded fuel system, drive shaft, etc. and 20 MPG vs 10. It's not a hard choice to make. The first major failure of either the motor or trans and I'm making the switch to LS.
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1972 C10 SWB, Air, PS, PB, 350/350THM. Second owner. 1965 Corvette roadster, 44K miles, 327/365 SHP, 4 speed, side exhaust, knockoffs, teak, second owner (bought in 1970), Have ALL numbers matching components. My frame off restoration thread: http://67-72chevytrucks.com/vboard/s...d.php?t=556703 |
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#21 |
Registered User
Join Date: Jul 2013
Location: Prescott Arizona
Posts: 343
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Re: LS vs 383
These 3 trucks all have Vortec 5.3s and the 4th (the Green one) is getting one soon. I'm prejudiced, we love 'em. If you know anyone with a Vortec or LSX V8 in one of our old 67-72 trucks ASK for a ride, you'll understand the Why part instantly.
It's funny to see the Carbed vs Fuel Injection discussions Again, really. If carbs are Still so good why are there almost Zero Vehicles produced Worldwide with them. The Worlds Fastest dragsters, Bonneville cars would probably run Carbs on top of their blowers, instead of injecting. I'll buy Nostalgia every time as a valid reason to Carb, but performance? I believe that ship has sailed and it ain't coming back.
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68 GMC SWB Vortec 5.3 98 Chevy Blazer ZR2 94 Mazda Miata, LS2 6 speed, sold "No matter what happens, nobody gets out alive" |
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#22 | |
Registered User
Join Date: Jan 2013
Location: San Antonio, TX
Posts: 733
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Re: LS vs 383
Quote:
__________________
Figure out what you want--then figure out what you are willing to give up to get it. |
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#23 |
Registered User
![]() Join Date: Jul 2010
Location: Las Vegas, NV
Posts: 969
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Re: LS vs 383
Nice trucks I really like the orange and white one..
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Mark 1972 C10 SWB LS1/T56 6 speed trans/4:56 posi with 5.5"-7" static drop/Boss 338 Wheels 18"x20" My build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=424609. My first start up http://youtu.be/R899YQ1OcjU |
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#24 |
Registered User
Join Date: Apr 2012
Location: Covington, GA
Posts: 386
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Re: LS vs 383
I paid $460 for a complete 4.8 with harness but no ECU or transmission. That included all accessories including the A/C compressor.
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Matt Cramer 1972 Chevy C10 - 4.8 swap, long bed, and maybe one dent free body panel somewhere - SOLD 4.8 LS build thread |
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#25 |
Registered User
![]() Join Date: Dec 2012
Location: Los Banos CA
Posts: 2,705
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Re: LS vs 383
I picked up a 2011 LC9 all aluminum / 6L80 trans with all drive accessories ecm pedal harness trans lines oil cooler lines shipped for under 3K. the short block I was going to build was almost $2K in partsd and I was going to have to rebuild myself. Of course there is all the other cost and learning curve..... but what I have seen so far in my build I am going to be happy happy happy!!!
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1956 Chevy Bel Air 2 door 1956 Chevy 210 4 Door 1970 K20 LWB project the Hulk build w/Supercharged 4.8L-ly2/4L60E HULK BUILD 1970 C10 Yellow/White Deluxe LWB w/ 5.3L-LC9/6L80E 1968 K10 LWB Dark green my son calls it "THE HULK Jr"HULK JR *SOLD* GO ![]() |
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