View Poll Results: 6.0 or 408
6.0
6
26.09%
408
17
73.91%
Multiple Choice Poll. Voters: 23. You may not vote on this poll
6.0 vs 408 Stroker
Thread Starter
Teching In
Joined: Feb 2022
Posts: 8
Likes: 2
6.0 vs 408 Stroker Hello Everyone,
I have a 2007.5 (nnbs) Chevy Silverado 5.3 LC9 with 225,000 miles. I am currently working on putting a 4l80e in it with trans go shift kit, deep pan, hardened shafts, bigger cooler, etc.
My questions is what engine should I pair it up? I can't deicide if I go 6.0 or stroked 6.0 (408). It would be N/A e85 to start off with. I would like 500whp but bare minimum 400whp. It is my second vehicle other than a daily so I would like it to be reliable. Later down the road, when the time is right and I have another truck. I'd like to turbo it with like s475 or s480 and make a decently reliable 800whp on low boost.
Thanks
I have a 2007.5 (nnbs) Chevy Silverado 5.3 LC9 with 225,000 miles. I am currently working on putting a 4l80e in it with trans go shift kit, deep pan, hardened shafts, bigger cooler, etc.
My questions is what engine should I pair it up? I can't deicide if I go 6.0 or stroked 6.0 (408). It would be N/A e85 to start off with. I would like 500whp but bare minimum 400whp. It is my second vehicle other than a daily so I would like it to be reliable. Later down the road, when the time is right and I have another truck. I'd like to turbo it with like s475 or s480 and make a decently reliable 800whp on low boost.
Thanks
With Forced Induction being the end game, I'd skip building a 408 stroker and do the 6.0 if it was my project. I can't really see needing the extra ~40 cubic inches and expense of a stroker crank (~$700+) when cranking up the boost a little more is an option to make up the difference.
If it was ultimately an NA build then definitely 408 stroker.
If it was ultimately an NA build then definitely 408 stroker.
Thread Starter
Teching In
Joined: Feb 2022
Posts: 8
Likes: 2
So what you'll are saying is the 6.0 is the way to go because I plan to have a turbo build? And if I was planning to do a na only build then the 408 stroker would be ideal/ the way to go?
Last edited by Silverado_z71; Feb 7, 2022 at 10:20 AM.
TECH Enthusiast
Joined: Dec 2012
Posts: 563
Likes: 3
From: Wilson n.c.
you can build the 408 and make the power easily but the power your looking for could be done with the stock cubic in. if the s475 or s480 is your turbo of choice i would go stock cubic inch.you culd actually make more than 800rwhp with the s475 and stock cubic in
TECH Senior Member
Joined: Jun 2016
Posts: 22,307
Likes: 3,622
From: Central Cal.
To hear Richard Holdener tell it, either build up a NA setup for large displacement, OR keep the engine stock with possible exception of the cam and slap a snail on it.
You adjust your power level by sizing the turbo accordingly.
You adjust your power level by sizing the turbo accordingly.
Trending Topics
There's been a lot of discussion over the years about this very topic. Wanted to share a few of the older threads. Hopefully, this will help provide more insight to the various benefits and draw backs of either choice.
6-0l-370-408-t91-turbo-850rwhp
370-408-boost
370-vs-408-one-why
I don't have a Forced Induction set up but I'd choose the 6.0 over the 408 if doing a FI set up as mentioned in post #2.
The 6.0 block a shorter lenght bore than even an LS. So even with correct piston selection to minimize piston rock there just isn't as much bore lenght to keep the piston stable with a 4 inch crank. There is enough for NA applications, even a ~250 shot or so but with BIG power adders that's another story.
Daily & reliable, 4 inch stroke motors tend to wear out quicker. Some NA will go ~170,000 miles+ but realistically ~50,000 miles to ~60,000 miles before bottom end needs a refresh. 3.62 stroke LS's can go much (3x) longer before needing refreshed.
This based on a discussion with my SAM graduate friend that built my NA 383 LS1 when we discussed power adders.
6-0l-370-408-t91-turbo-850rwhp
370-408-boost
370-vs-408-one-why
I don't have a Forced Induction set up but I'd choose the 6.0 over the 408 if doing a FI set up as mentioned in post #2.
The 6.0 block a shorter lenght bore than even an LS. So even with correct piston selection to minimize piston rock there just isn't as much bore lenght to keep the piston stable with a 4 inch crank. There is enough for NA applications, even a ~250 shot or so but with BIG power adders that's another story.
Daily & reliable, 4 inch stroke motors tend to wear out quicker. Some NA will go ~170,000 miles+ but realistically ~50,000 miles to ~60,000 miles before bottom end needs a refresh. 3.62 stroke LS's can go much (3x) longer before needing refreshed.
This based on a discussion with my SAM graduate friend that built my NA 383 LS1 when we discussed power adders.
Last edited by 99 Black Bird T/A; Feb 7, 2022 at 10:48 AM.
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Verdad Gallardo TECH Senior Member
Joined: Jun 2016
Posts: 22,307
Likes: 3,622
From: Central Cal.
If the turbo comes later, then yeah go displacement, BUT if the turbo is going on now, leave the engine alone for the most part and let manifold pressure compensate for displacement.
Joined: May 2004
Posts: 1,593
Likes: 267
From: Halfway back on the Highway to Hell...again!
First, No replacement for displacement
2nd, I suggest stay as close to stock bore as possible. So build a 402 if the walls are good. No need to bore that .030 if you don't need to.
3rd, add boost to that 402 with a 6.125 rod combo and you'll make more power than that stock 6.0.
Also the stroker, if it has the right cam and matching components, can make greater torque before boost and will be a much better cruiser until you "need" boost. Pushing a 5k+ lbs truck is quite different than most of the 3k lbs cars guys are used to building for.
2nd, I suggest stay as close to stock bore as possible. So build a 402 if the walls are good. No need to bore that .030 if you don't need to.
3rd, add boost to that 402 with a 6.125 rod combo and you'll make more power than that stock 6.0.
Also the stroker, if it has the right cam and matching components, can make greater torque before boost and will be a much better cruiser until you "need" boost. Pushing a 5k+ lbs truck is quite different than most of the 3k lbs cars guys are used to building for.
On The Tree
Joined: Jun 2019
Posts: 184
Likes: 66
From: HTown, Texas
On The Tree
Joined: Jun 2019
Posts: 184
Likes: 66
From: HTown, Texas
TECH Fanatic
Joined: Dec 2019
Posts: 1,129
Likes: 478
If both a 4.8 and a 408 can make more power with pump gas than is useable on the street, what's the benefit of the larger engine?
I've made almost 1100 horsepower with a stock short block 4.8. There was nothing to gain other than wallet weight reduction doing so with a 408.
If anything the extra low-mid range torque would have made traction harder to maintain with the larger engine, making the smaller engine quicker.
Before you say its "easier", it really isn't.
A lower numerical boost number means almost nothing in most situations and you couldn't even give me an area of additional stress caused by this that would even be of any concern.
The heat of compression from boost pressure can be mitigated by an intercooler. Its entirely possible to get less heat into the intake from high boost than it would be on an N/A engine.
The heat of compression in the cylinder is based purely on pressure differential before/after (compression ratio) as well as starting temperature and is unaffected by the initial boost pressure going into the cylinder.
So that old school mentality of big engine and 6 PSI is mainly because tuning and technology were so lacking.
I come from a history of blown big blocks. 454 through 632, with a everything from a 671 to a 1471 on top as well as most of the popular offerings in centrifugal supercharging from Vortech to Procharger.
Its just easier to turn up the boost then to replace the entire engine to get a number lower when it has significantly less effect than most people think it does.
I've made almost 1100 horsepower with a stock short block 4.8. There was nothing to gain other than wallet weight reduction doing so with a 408.
If anything the extra low-mid range torque would have made traction harder to maintain with the larger engine, making the smaller engine quicker.
Before you say its "easier", it really isn't.
A lower numerical boost number means almost nothing in most situations and you couldn't even give me an area of additional stress caused by this that would even be of any concern.
The heat of compression from boost pressure can be mitigated by an intercooler. Its entirely possible to get less heat into the intake from high boost than it would be on an N/A engine.
The heat of compression in the cylinder is based purely on pressure differential before/after (compression ratio) as well as starting temperature and is unaffected by the initial boost pressure going into the cylinder.
So that old school mentality of big engine and 6 PSI is mainly because tuning and technology were so lacking.
I come from a history of blown big blocks. 454 through 632, with a everything from a 671 to a 1471 on top as well as most of the popular offerings in centrifugal supercharging from Vortech to Procharger.
Its just easier to turn up the boost then to replace the entire engine to get a number lower when it has significantly less effect than most people think it does.
Some 1500's don't weight much more than modern sedans. For instance difference between a CTSV vs OP's truck might only be 200-300lbs, no different than having a passenger or two.
Pretty much, size the turbo correctly and you can make a ton more torque earlier than any stroker engine would. Granted all that does on the street is a smoke show.
Pretty much, size the turbo correctly and you can make a ton more torque earlier than any stroker engine would. Granted all that does on the street is a smoke show.
On The Tree
Joined: Jun 2019
Posts: 184
Likes: 66
From: HTown, Texas
On The Tree
Joined: Jun 2019
Posts: 184
Likes: 66
From: HTown, Texas
The main benefit is the part throttle characteristics. I can't stand how slow my car is just cruising around at part throttle, and my little 4.8L doesn't even make 600whp. It only gets fun when it's in boost and I don't want to look like one of these straight pipe nissan 350z goons going WOT from every stoplight.
Maybe at WOT and in full boost, but I'm talking about a street engine that is driven on the street and spends a lot of time at part throttle. The bigger engine will accelerate better with less throttle and less RPM than the smaller engine. Regardless, for WOT performance that sounds like a scenario that can be fixed by going to a lower numerical gear ratio which would usually be favorable for a street car.
Except when it isn't. In my personal experience, I'm at a limit of about 14psi that the factory ECU can read. It's a street car that needs to pass OBD-II inspection so no aftermarket ECU for me. Even if I could, turning up the boost isn't going to fix how lazy my little 4.8L feels when it still has manifold vacuum. I could go up in gear, but so will my RPM at every MPH. I might be able to find a smaller turbo to spool sooner, but then it might run out of breath sooner. Cubic inches just seems like the best path forward. I can see your point for a race car, but based on my personal experience, displacement seems VERY relevant for a street car.
Maybe at WOT and in full boost, but I'm talking about a street engine that is driven on the street and spends a lot of time at part throttle. The bigger engine will accelerate better with less throttle and less RPM than the smaller engine. Regardless, for WOT performance that sounds like a scenario that can be fixed by going to a lower numerical gear ratio which would usually be favorable for a street car.
Except when it isn't. In my personal experience, I'm at a limit of about 14psi that the factory ECU can read. It's a street car that needs to pass OBD-II inspection so no aftermarket ECU for me. Even if I could, turning up the boost isn't going to fix how lazy my little 4.8L feels when it still has manifold vacuum. I could go up in gear, but so will my RPM at every MPH. I might be able to find a smaller turbo to spool sooner, but then it might run out of breath sooner. Cubic inches just seems like the best path forward. I can see your point for a race car, but based on my personal experience, displacement seems VERY relevant for a street car.
Modern sedans and 1500's have run 8's with a 5.3L so apparently they get moving just fine. How fast do you want a street truck to be?