383 Stroker or 6.0 LS??

[Rashad Baker]

I cant decide on going with the 383 stroker/700r4 TCI built trans w/EFI kit or the 6.0/4L80E LS in my 90 Suburban 4x4. Right now it has the 5.7 350 TBI 700r4 and 3.73 gears.

I am planning on using it for towing, daily driving, and cross country trips (Atlanta to California) so I am looking for reliability and decent MPG. It seems like I can get good HP and torque and decent MPG (including the EFI kit) by going with the 383 while keeping it simple without having to spend all of the extra money for an LS swap.

Are the LS engines that much reliable and efficient than the 383? What kind of mileage would I get with a 383 or 6.0 LS engine for those of you who are currently running these setups?

Thank you in advance for your replies, I keep going back and forth on my decision.....

 

[Vbb199]

My vote is to keep her small block. Run the 383.
BUT, the efi won't make better mpg.
The LS will.
The efi just keeps her running smoothly and starts up easily.

The 383 also won't make the kinda power the LS will sadly.
As a man who runs nothing but classic sbc power, I can fold and be willing to say "the old school performance doesn't make the kinda power an LS can"

I just simply kick the LS to the curb to be a rebel, and because it's overdone.

That might not be your cup of tea, but if I added coil packs, cam and crank position sensors to my 502 bbc, I'd be making power that'd put all the LS fanboys to shame.

Seems to be give and take. LS is alot of work, while 383 is just a simple swap.

 

[Vbb199]

If you're going the 383 route, you'll need a new ECM burned, and have the tbi and it's intake bored out, as well as run a higher PSI fuel pump... I think you'd need 14 psi instead of the stock 12 psi for a 5.7 tbi

 

[shiftpro]

My vote is to keep her small block. Run the 383.
BUT, the efi won't make better mpg.
The LS will.
The efi just keeps her running smoothly and starts up easily.

The 383 also won't make the kinda power the LS will sadly.
As a man who runs nothing but classic sbc power, I can fold and be willing to say "the old school performance doesn't make the kinda power an LS can"

I just simply kick the LS to the curb to be a rebel, and because it's overdone.

That might not be your cup of tea, but if I added coil packs, cam and crank position sensors to my 502 bbc, I'd be making power that'd put all the LS fanboys to shame.

Seems to be give and take. LS is alot of work, while 383 is just a simple swap.

Some good points here but it's not fair to say the LS will produce more power... you don't know what he has for heads.. Ultimately it's all in the heads as you know. Doesn't matter how many cubes you have, if the heads don't flow the tires don't smoke.

Rashad...? Heads my man... whachoo gonna run?

 

[Vbb199]

Some good points here but it's not fair to say the LS will produce more power... you don't know what he has for heads.. Ultimately it's all in the heads as you know. Doesn't matter how many cubes you have, if the heads don't flow the tires don't smoke.

Rashad...? Heads my man... whachoo gonna run?

True this.
A nice cast iron set or aftermarket aluminum set of vortec heads on this said 383 would really make some impressive power.

 

[Rashad Baker]

My vote is to keep her small block. Run the 383.
BUT, the efi won't make better mpg.
The LS will.
The efi just keeps her running smoothly and starts up easily.

The 383 also won't make the kinda power the LS will sadly.
As a man who runs nothing but classic sbc power, I can fold and be willing to say "the old school performance doesn't make the kinda power an LS can"

I just simply kick the LS to the curb to be a rebel, and because it's overdone.

That might not be your cup of tea, but if I added coil packs, cam and crank position sensors to my 502 bbc, I'd be making power that'd put all the LS fanboys to shame.

Seems to be give and take. LS is alot of work, while 383 is just a simple swap.

Thanks for your thoughts. I’m not really trying to get the absolute most power, just enough that it will handle handling the towing that I plan to do (59 Divco 4K lbs) and reliable enough to drive across country with decent mileage. How much more efficient is the LS? Does it justify the extra cost?


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[Rashad Baker]

Some good points here but it's not fair to say the LS will produce more power... you don't know what he has for heads.. Ultimately it's all in the heads as you know. Doesn't matter how many cubes you have, if the heads don't flow the tires don't smoke.

Rashad...? Heads my man... whachoo gonna run?

I am planning on vortex heads!


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[Vbb199]

Thanks for your thoughts. I’m not really trying to get the absolute most power, just enough that it will handle handling the towing that I plan to do (59 Divco 4K lbs) and reliable enough to drive across country with decent mileage. How much more efficient is the LS? Does it justify the extra cost?


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If you're doing just 4k pounds, I don't see why a tbi 5.7 and 700r4 is such a bad thing.

She'll safely do 6-7000.
Anything more, you're gonna need a temp gauge for the tranny, coolers, etc.

(I might get a flaming for that statement, we got alot of 700 haters here lol)

I Will say IF you was to do that, I'd change the fluid and filter after every 3 or 4 long pulls.
If she's going out the door with 250k miles on her, slips, flares, etc, don't risk it lol.

 

[Rashad Baker]

If you're doing just 4k pounds, I don't see why a tbi 5.7 and 700r4 is such a bad thing.

She'll safely do 6-7000.
Anything more, you're gonna need a temp gauge for the tranny, coolers, etc.

(I might get a flaming for that statement, we got alot of 700 haters here lol)

Well my bad on that, it will be about 6k with trailer weight. I hear a lot of horror stories about towing with the 5.7 tbi in the mountains, I’d rather have more and not need it rather then not enough and be SOL lol


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[Vbb199]

The MPG you're angling to get is all relative to tire size and gear ratio.

I've had people argue, but I've gotten 20-22 mpg on a 3.08 geared burban with stock tire size.
If you're angling to get ok MPG, just don't go running 4.56's on a small tire or some weird ****.

There's a nice balance on ratio and tire size with towing.

 

[Vbb199]

Well my bad on that, it will be about 6k with trailer weight. I hear a lot of horror stories about towing with the 5.7 tbi in the mountains, I’d rather have more and not need it rather then not enough and be SOL lol


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What did you plan on putting behind the said 6L LS?
I assume a 4L80e if you wanna supercede the 700r4.

 

[Rashad Baker]

The MPG you're angling to get is all relative to tire size and gear ratio.

I've had people argue, but I've gotten 20-22 mpg on a 3.08 geared burban with stock tire size.
If you're angling to get ok MPG, just don't go running 4.56's on a small tire or some weird ****.

There's a nice balance on ratio and tire size with towing.

I’m running 3.73 gears and LT265/70/17 tires


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[Rashad Baker]

What did you plan on putting behind the said 6L LS?
I assume a 4L80e if you wanna supercede the 700r4.

Yup the 4L80E


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[eskimomann209]

I like the LS. If you can find a nice used 6.0 in my opinion you’re dollars and donuts ahead of a 383 build. Burb being a 90 youre golden with the Driver drop 241 with a VSS and the correct speedometer. That’s a lot of the battle done. Your fuel sender just needs a 30$ pump installed on it. Fuel lines are easy peasy.
you have a great starting base mah man.

 

[shiftpro]

I am planning on vortex heads!


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Good choice..
And you need compression... at least 9.1 or better yet 9.5. You can still run pump gas. You will out torque
the LS with this setup.
i just love the power band on 383s.. just touch the go pedal and your back feels the seat pushing into it.