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Discussion Starter · #1 ·
Hi all!

So im working on a junkyard ls build- either 5.3 or 6.0 - probably with 706 heads (i might port them a little).. Probably planning on keeping bottom end stock-

Ill be running a carb setup prob with the msd ls kit-

77 camaro, 373 rears, 2004r, 3000k stall, long tube headers (not sure what od - what size would you recommend?)..

I currently have a 350 with the GM hotcam, and was planning on going 383 (might still do that) - it was super fun to drive, when you stomp it the motor just screams and hauls.. plus i get 23mpg highway-

Anyway- any cam recommendations based on my setup? I want to price out an LS vs 383 build-
 

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Leave the cam alone. The factory cam is fine for most situations.
This also allows you to keep the engine stock making the swap a plug and play thing (with a manual or brainless automatic).

While running something like a ls9 cam may seem good on paper it will cost you torque down low where your going to spend a majority of your time. Cam bearings on a LS engine will basically eliminate the "budget" aspect.

A carburetor on a LS is also a proven bad idea. The factory fuel injection system can put out some impressive numbers. You start tuning or adding forced induction and the design is still up to the task.


If you want to keep this thing budget based. Grab a 5.3, with the manifolds, the harness, and computer. Run the engine on half a dozen wires after you flash the VATS out. Mate the thing up to a th400 or 4 speed manual and drive.
It can be done for 2k sloppy or for 3-4k nice.


Here you go buddy.
 

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Discussion Starter · #3 ·
cerial - how old are you (no offense)? Really not trying to be a jerk but if youve been around motors long enough that would be one of the last things you would mention.. carbs can make just about as much power as efi and run just as good so thats seriously not even a consideration sorry-
 

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I'm not a fan of a carb on an LS either. But it will work, but it asks why.

I'm guessing budget is a concern. If you were to take the money you're going to spend for ignition, oil pan, intake, motor mounts and headers and invest that in a set of heads for a 383, then you'll be farther ahead than you will be with 325 or 364 cube LS.

The LS advantage is in bottom end strength and stock head flow. You're not going to hit the limit of the Gen 1 bottom end and equivalent head flow can be found in a Gen1 aftermarket head. The LS starts making sense when you're looking at 600+ whp IMO.

Of course there is the guy that wants what he wants, so you ought to do what will make you happy.
 

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cerial - how old are you (no offense)? Really not trying to be a jerk but if youve been around motors long enough that would be one of the last things you would mention.. carbs can make just about as much power as efi and run just as good so thats seriously not even a consideration sorry-
I recently just tuned 40.
I been modifying cars since I was 12. Before that it was lawnmower and snowmobile engines powering golf carts and gocarts.
Father had a auto body business, uncle had a towing business.
I have personally titled over 100 cars.
I have driven over 80 of those
Wheels up when stopped 6
End over End 1
Caught trees 4
To many slide off's and recovery's to mention

My current preference is Chevy, Toyota, Mazda, Honda, Ford, Tesla in that order


I am not against carburetors. You run a series 1 beetle or a MGB or a Mini that thing will do just fine with a carb. I love side drafts in general and especially on motorcycles. I scare other people and frankly myself on bikes so I stay off of them.



What I am against is taking something that works and going backwards because your afraid of it. Furthermore doing this when it will waste money to do so.


I grew up tuning very dumb fuel injection when tuning these systems was hard. Slapping a carb onto something back in the Early 90's made sense. It eliminated the limitations. But around 2000 systems became easier to tune and things began to get better across the board. You were finding consumer engines with forged internals, overhead cams, aluminum blocks, that were putting out impressive numbers with and without forced induction.
Jump ahead 10 years and there is a power jump as everything is running a turbo or higher compression. You see consumer engines with DLC materials and active fuel management several times smarter then those dumb 90's setups and much smarter then carburetiors.
Jump ahead another 10 years(2020) and things have settled down a bit focused mostly on safety. Just in time to get into when the electric/ice battle is really starting to heat up.
Once a mass produced easy to convert to standalone AC motor hits the market with a pack that is able to convert a ice engine over for under $5000(parts) it will change the game. We are not there yet(battery or charging station wise either) so everyone is still using the good old LS. Maybe 2030 maybe later you will be able to take that classic Chevelle pull out the entire drive train, Slap a battery pack/controller under the hood and have a electric axle out back that will crush even engines making boost in the 20's.



To run a carb on a LS engine you need to drop around a grand into parts to make the conversion. The benefit is that it is "simple". But, the thing is that it is not.
Your taking a system that is highly adaptable to several situations instantaneously and replaced it with a vacuum based carb where the adjustments and timing run on a fixed curve.
This means that when you push the limits of lets just say compression and come across some junk fuel that carburetor is going to have that engine running horribly. Other things to consider are elevation changes, ambient temperature, and around a dozen more that a factory LS fuel system just does better then a Carburetor.

They had the sense to keep it port injection not direct so the injectors last. They used individual computer controlled coils(learning the lesson from omnispark) so the spark is strong and easily adjusted, they stuck with a simple proven throttle body design, they even kept the single cam push rod design(Something I was hoping the C8 would change). Most importantly they kept the fuel mapping simple. Simple enough that even if you have never tuned a engine before you can take someones seup that is close to your setup and run there map being close to perfect.

It has been refined into a platform where you can do what you want with it and you do not need to jump through complicated tuning hoops to do it.

You want to talk simple.
Rebuild a classic 70's Edelbrock then rebuild a TBI throttle body.
Change jets at a rest stop then adjust the fuel map on a LS engine
Buy a SBC that someone else has heavily modified requiring hours of detective work on what has been done or plug in a programmer into a fuel injected engine to see what is actually going on.

Some setups are just good for the application and do not need modification. You play with enough engines and you will find the benefits and pitfalls of every type of engine. If you are happy running a carburetor on a carbureted engine or a early fuel injected engine then run it. But taking something that works and going backwards just to do so.

Your money man if your more happy with a carburetor save yourself the headaches and run the 383
 

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Rod...from a Chrysler?
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I recently did a 5.3 swap. It has a stock cam from a 6.0. For the track, 14.1 seconds in a 69 El Camino. I'm sure a bit more tuning and it will go into the 13's.
Doing it again, the 6.0 is the way I would go. Bigger is better.
For driving on the streets, the 5.3 is plenty good enough though.
 
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Discussion Starter · #8 ·
Ok so you have prompted my attention.. here is an article i thought was kind of to the point-


I think what im gonna do is go back to my 350 with ported heads and get as much power from it as possible, then go 383-

and then drop in a ls6 and shoot a nice vlog along the way- would be fun to have some 1/4 times, mpg comparisons-

What would I need ecu wise from the junk yard? basically all the wires around motor and to ecu and i should be able to run it as is correct?
 

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Get the complete engine harness all the way to tranny, O2, sensors, etc.
Watch out for year. Later motors have DOD. I chose a 2004 unit. No BS to deal with.
 
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Discussion Starter · #10 ·
Get the complete engine harness all the way to tranny, O2, sensors, etc.
Watch out for year. Later motors have DOD. I chose a 2004 unit. No BS to deal with.
yeah i noted that today- stick with the older (pre 07?) motors- hoping to find a 6.0 and 706 heads- whats the deal with the front vs rear cam pickup? newer ones had front cam?
 

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If you want to tune it yourself, implying that you'll be buying HP Tuners for a stock ECM, I'd strongly recommend against it. Buy a Holley kit or Megasquirt. (MS if using a TH350, 400 or manual trans) - cheaper and easier if the chassis was never offered with an LS in it originally. There is nothing wrong with going with a stock ECU if, repeat if, you want to run a stockish motor and are prepared to drop $700 on HPTuners.

You want a Pre VVT engine. DOD/AFM is an easy workaround that costs less than $100 to delete. If your goal is over 600hp, then stick with Gen4 (post 2005) motors with the big rods. The difference in cam pickup is 24x (rear) vs 58x (front) cam pickup. Both are fine and can be swapped inbetween witha couple of connectors and some repinning on the sensors.
 

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I have linked this video about a dozen times on here at this point. The guy just does a good job at showing what it really takes and just how easy it is.

Now this is the messy version. But if you go to lt1swap.com.

They have basically walkt hroughs showing what pins to pull and such to modify the harness. Or if your not up for that you can simply buy one already setup. This will work great for stock. If you want to go further then Megasquirt is my go to and the Megasquirt forum'shave probally already covered basically whatever you have in mind showing the maps and such to make it all work.
 

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Discussion Starter · #14 ·
hi guys thanks gr8 info.. yes all the vids i saw were a bunch of (not sure what word to use here) with shaky cams and literally nothing concrete, just a bunch of rambling on and on about trash - drives me freaking nuts! YouTube should have ratings!

Cool ill look it up- gonna hit the yward today and look for a 6.0 - im prob gonna do a cam upgrade at most- so will pull ecu too, throw in a shallow car oil pan onto the truck motor - accs are more accessible and the truck intakes are good - sooo all depends- plus the (L96?) heads with offset rockers - alot to scour!

Any idea if any cars came with turbos that might work on these down the road?
 

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Junkyards will charge you for every part of that engine.
Your better off finding a truck or van being parted out. Often the harness, ecm, and complete 5.3 engine can be had for $500. Around here anyway.

If your thinking boost then run a 5.3. The reason is availability. Around here I can hit more then 20 decent 5.3 motors before I find one repairable 6.0. You can run the 5.3 shortblock on boost stock(with minior changes) and have a $500 spare with several other spare parts attached ready to swap over.
That boost video shown above is a rough playbook/expected power output of a stock cam/heads engine. Tons of tech on megasquirt and lt1 stie on running single digit boost on stock motors as well as small changes to run additional boost.

I like to build in stages.
Get the engine in,
Fine tune suspension/handling/stopping
Then look at adding power
 

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Discussion Starter · #16 ·
before I find one repairable 6.0. You can run the 5.3 short
Yeah ive pretty much decided ona 5., and wanna throw on the 706 heads.. found 2 today - question is, some of the ecu wiring is cut here and there.. and some parts missing - so id wanna make sure everything is on b4 i check out-

Will a ecu from a different 8th digit vin letter work? 4 5.3s at the yard today but i was so exhausted from work might go back in the morning- 2 had trannies out so will be easy..
 

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Forget the junkyard.
You hit the junkyard for good shortblocks. All those small parts like intake, coil packs, throttle body, acessories, etc will add up to a $700-1000 depending on who is working engine.

You can get a complete engine from a part out for a average of $500 and maybe even get to see the thing run before it is pulled.
Give them half down and tell them to save the harness, come back the next weekend to load the thing up.

Or if you have the room to part one out. Buy a entire 200k truck with a good engine for $800-1000. Part it out and get a $500(or less) engine that way.
Usually with a junk 4l60e behind it but the axles, wheels/tires, interior, bed, body panel's, rolling chassis(with cab/title), etc will recoup some of the cost.
 

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Discussion Starter · #19 ·
i can get a complete engine with all the junk for under 300- fixed pricing, they dont discriminate between engine size/etc.. doesnt matter if u buy a 4 banger motor or 10 cyl v8 - same price for a complete engine - fixed pricing

Im prob gonna stick with the gen 3 LS - and grab the stock harness and ecu and reprogram that.. saves me the $$ for the extra junk - i can pretty much get a stock running ls for under 300 - gonna pull 706 heads and pop em on the 5.3.. thats the plan.. and maybe add a turbo later (which i why ill grab the cut off headers - for the flange fittings/etc)..

Thats basically my plan - was gonna go today but have to finish up a customers job - so maybe 2moro morning first thing
 
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