6.0 LS or build a 406?

[olblue81]

Just thinking about the direction I want to head. I've got a 400 sitting in the barn that I had planned to build up for my truck, but I'm wondering about going with an LS motor. I'm approaching this from a practical perspective. I want to enjoy driving my truck. There isn't an unlimited bank account in my house so I have to make the most out of my $ spent.

I like the idea of the modern engine from a practical stand point. They'll make more power and burn less fuel than a traditional sbc and that means getting to enjoy driving the truck more. But LS swaps are getting dime a dozen anymore (no offence to those that have them) so the wow factor is diminishing.

But I like the sbc from a traditional standpoint. It's what they came with from the factory, so at the first glance it could look kinda stock. I'm not sure how many more years the aftermarket will cater to the sbc. There not in production anymore so now might be the best opportunity to buy new high performance parts.

Just wondering what others have thought about this subject.

[pcmcobra]

go with the ls...you will NOT be disappointed.

[JW76]

I like the old school motors, but the LS is awesome. 6 bolt mains, runs .500 lift stock huge flow number on the heads. They make huge power with stock components designed for a hard lifetime of daily use. They are made to run todays fuels and oils. To build a comparable Gen I you would have to push the limits of the engines durability and reliability and use radical performance parts drastically reducing the engines life expectancy. The LS does this without breaking a sweat still having a 200000 mile lifetime. Carb the LS and get rid of all the wiring hassle and you get the best of both worlds plus you get better gas mileage than a Gen I. WIth the added life of the motor, you'd probably easily offset the higher initial investment. Good luck with your decision.

[olblue81]

Originally Posted by JW76

I like the old school motors, but the LS is awesome. 6 bolt mains, runs .500 lift stock huge flow number on the heads. They make huge power with stock components designed for a hard lifetime of daily use. They are made to run todays fuels and oils. To build a comparable Gen I you would have to push the limits of the engines durability and reliability and use radical performance parts drastically reducing the engines life expectancy. The LS does this without breaking a sweat still having a 200000 mile lifetime. Carb the LS and get rid of all the wiring hassle and you get the best of both worlds plus you get better gas mileage than a Gen I. WIth the added life of the motor, you'd probably easily offset the higher initial investment. Good luck with your decision.

You hit the nail on the head with this one. The LS are sooooo much better. It'd take a ton of aftermarket parts to make 1.2 hp/in with a 406 and a 6.0 can do that with a cam swap. Plus start at the flick of the key and pull down 17+ mpg to boot.

The LS motor swap would probably be cheaper to. Don't think I could do the 406 the way I want for less than $5k in parts and my insurance company has 3 2001 engines for $1800-2100. They have 105k to 174k on them, so they would need some freshening, but if I step up the something newer with drive by wire throttle body they have 6 for the same price with as little as 13k on them.

I'm kinda talking myself out of the 406 aren't I?

[Tom]

Go 6.0, or even better get a LSX block and go 7.0. Ls motors are the way to go for power. Im finishing up my years in the making 388 genI and then not spending another dime on it performance wise. It will be all LS from now on.

[N2TRUX]

LSx by all means. Just don't carb it. You will be happy with the electronics once your set up. As money permits do a cam/head swap and crank out 500hp while get 20mpg...that ...

[olblue81]

Originally Posted by N2TRUX

LSx by all means. Just don't carb it. You will be happy with the electronics once your set up. As money permits do a cam/head swap and crank out 500hp while get 20mpg...that ...

That brings me to the next question about doing a 6.0, the electronics. Do guys get the computer from the donor vehicle and get an aftermarket harness? What about tuning?

[AceX]

I recommend an aftermarket harness. They can be had anywhere from $600-$1200 depending on your needs.

Speartech, Current Performance, and GMPP all offer top of the line, customizeable harnesses for LS motors.

Also, which flavor of LS motor you pick can make a world of difference. I found my dream motor in the new 6.2L from the GMT900 platform ('07-present trucks), but many LS1, LS2, and LS6 engines are out there for cheap. I've seen a few LS1's w/ harness sell for less than $2k. An LS2 or LS6 will cost a bit more, but offer a better top end and of course, more power. In any case, you can't lose with these motors. Find a solid 4L80 or 4L65 to put behind it and let the good times roll.

[kevinr1970]

I saw a wrecking company down in OR that had a '07 3/4 2wd truck (17k miles) that looked like it had been damaged on every body panel but the add said "lot drives".
The truck was ~$5000 complete.
If I understand the ad correctly it had a 6-speed automatic with a 6.2l. I am not familiar with these newest style trucks but was it a misprint and it is a 6sp manual or are they coming with 6sp automatics now?
If it is an auto, is this tranny worth considering for a hotrod application?

[Justins76]

Maybe it was an Allison transmission?

[Cherub]

There are so many options and route to go when placing a LSX motor into a square body. I would first set your budget then work back from there. Cause trust me it adds up fast. brp has good motor mounts but are more expensive than the plate type found on ebay. there are several options for headers from stock to mid length from s&p to long from brp. Like mentioned above you can get a new wire harness or have the existing one reworked. Not everywhere reworks them, so you will have to call around.

Getting a drive by wire engine and converting to DBC is simple (DBC throttle body and splice a few sensors.)

Ok that being said you will love the power and reliability that the LSX allows you. On the internet the swap is pretty common, but i gaurentee that if you take it out and show people they will still be impressed.

[D13]

6 speed auto on the latest LSX. It's slick for MPG. But as far as I have seen it's 4wd only in trucks. If you get it be sure to get all the electronics and wiring as there is very little aftermarket support for them yet.

[swb85]

Both LS and SBC motors have their place. I currently have both, have built both, have made good power with both. For what you're doing I'd probably go LS. The streetability for a given HP level is far beyond the SBC and the power potential is far greater per dollar spent...... just looking at them funny picks up 15hp. Seriously. They are getting pretty common in salvage yards nowadays, around here you can pick up a complete 5.3 for $350 any day of the week.

[AceX]

On the 6spd Auto;

The 6L80E was first introduced in the GMT900 chasis and was placed behind the 6.2L motor found in the Escalade and Denali. At first it was only offered as a full-time AWD unit, but has since been given the 2wd treatment, starting in either late 2007 or early 2008.

The overall length of the unit is not much longer that the 4L80E, but it is much larger in the mid section.

I have an AWD version of the unit sitting in a warehouse right now patiently waiting for me to tear into it.

[kevinr1970]

So is the 6l80e a good part given the application or would it be better to look for something with a 4l80 transmission?
The application would be in my 2wd K5 and is still down the road a bit.

[Captkaos]

LS all the way. If it isn't enough power, I can sell you an STS Setup for it...

TOM, where have you been?

[AceX]

Originally Posted by kevinr1970

So is the 6l80e a good part given the application or would it be better to look for something with a 4l80 transmission?
The application would be in my 2wd K5 and is still down the road a bit.

4L80's are much more plentiful and there is solid aftermarket support for them as well. Thus far, I can't find anything for a 6L80E that doesn't come from GM.

I plan to use the 6L80E that I have for CARB certification on my engine swap, then I have a big decsion to make; Swap in a 4L80E, or go AWD. One is easier, the other is more fun...

[dan76]

I recently saw a local truck (69 GMC 3/4 ton 2wd) equipped with a 6.2 and matching trans. It was impressive. The owner said he bought the engine trans combo with all accessories and had the wiring harness worked to remove unneeded issues (VATs for one). The truck is now a daily driver with 18+ mpg, tows like a banshee and has cold A/C.

[silvereagle07]

TCI recently released a 6 spd auto. Here's a link.
http://www.tciauto.com/whatsnew/File...ansmission.pdf

[68 TT]

It all depends upon your power goal and your budget.

I love the 6.0+ LS motors and will eventually build one for my truck and my Camaro but they are pretty expensive to get, wire, plumb and tune.

You can build a 406 to make right at 350 hp with common 1.94 valve truck heads and a fairly mild hydraulic flat tappet cam for right at $2500 complete and it will drop right into your truck without changing a thing. I have this combination in my Malibu and it has been strong & reliable for the past 12 years.

You will easily have $4000 into a stock 6.0 swap if you count all the cost of a custom wire harness, custom computer program to remove VATS (or buying the software to do it yourself), the custom headers, custom radiator, custom fuel system, etc...

If you want to make more than about 350 hp then the 406 gets expensive very quickly. A decent pair of aftermarket heads put it right at the cost of the 6.0 swap but when you throw in a steel crank & good rods you go way past the 6.0 swap.

As stated earlier a simple cam swap in the 6.0 can build amazing power with no other changes except tuning for the cam.

If you are going to do the 6.0 swap then I would suggest you buy the software to tune it yourself. It will pay for itself many times over the life of the truck and any modifications you do to it.

[pcmcobra]

speartech and mast motorsports have what you need for the 6l80e

[nico]

I am having the same problem... 406 vs. 6.0, and am trying to take into consideration all the parts I already have (all accessories, exhaust, new aluminum radiator and cooling system, etc.).

I am very happy with my current Demon carb setup and my fresh 700R4, and would want to keep both, even with a 6.0, which complicates the 6.0 swap.

I have nearly decided on a 406, with forged 22cc dish pistons, six-inch rods, vortec heads and a Comp 12-212 and a Performer RPM Air-Gap (which I already have the cam and intake)... All my desktop dyno runs and internet/magazine/machine shop research says it should be around 425 hp and 525 lb. ft., and use my existing exhaust and accessories.

[Driveway Dreams]

Originally Posted by kevinr1970

...was it a misprint and it is a 6sp manual or are they coming with 6sp automatics now?

The 6 speed automatic tranny is standard on the 3/4 and 1 ton trucks. The 1/2 tons can have them too behind the 5.3 or 6.2, and the Yukon/Tahoe/Escalade lines get them as well. It has seemed to be a very nice transmission for those trucks, and the driveability is great. When they back the 6.0 on a 3/4 or 1 ton truck, (even in the big truck) it is a fun combo.

[SMiller]

Why no 8.1\Allison combo?

[D13]

8.1's make decent torque but don't rev fast and suck gas like crazy. While Allisons are very stout they aren't particularly efficient and not much on performance.
8.1 / Allison is a great dually hauler combo but just not much fun to drive compared to 6.0/4L80E.