When you reach a fork in the road, take it.

[Sle-z_90]

The other benefit to planning to use a th400 is that I could just see how long the 700r4 will last and kick the transmission cost down the road some.

 

[Sle-z_90]

Haters gonna hate. If you're planning on dropping a 6.0 in the truck in your profile pic, it will be severely traction limited.

Spinning 'em is part of my goal, although I'd like to lower it, upgrade the brakes, and add posi at some point.

 

[HotWheelsBurban]

Overdrive, to me, is more necessary on the highway, and at higher speeds. But it has benefits at the lower speeds too; any time the transmission is in overdrive, the engine is turning lower RPM so it should be more efficient.

 

[L31MaxExpress]

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Thank you for proving my point, that thing is crawling at lower rpm. With the LS6 cam, I bet it does not make 270 ft/lbs at 2,000 rpm.

 

[L31MaxExpress]

Overdrive, to me, is more necessary on the highway, and at higher speeds. But it has benefits at the lower speeds too; any time the transmission is in overdrive, the engine is turning lower RPM so it should be more efficient.

Lower rpm does not necessarily mean better efficiency.

 

[0xDEADBEEF]

Thank you for proving my point, that thing is crawling at lower rpm. With the LS6 cam, I bet it does not make 270 ft/lbs at 2,000 rpm.

LOL, whatever. I'm barely on the throttle.

BTW, RPM and speed are fixed. It doesn't matter how much torque you make. 2k rpms in a certain gear is always the same speed.

Also, I totally agree about the torque numbers. The heads and cam hurt low end torque, so I'm making less than a stock 5.3 would.

 

[OutlawDrifter]

What is considered "lower mileage?" I was thinking if I could find one that is still in the truck that I can hearing running and that has less than 150k on it. I could just stab it in as is. If I go to the junkyard and pull one, I would want to at least do rings and gaskets. Is there a rule of thumb on this?

130k or less would be "low mileage" in my opinion...even then I would put an oil pump and timing chain in it just for cheap insurance. Why would you do rings? If it needs rings, move on and find another. I've pulled LS's apart with over 200k miles that still have the factory crosshatch in the bores. Shouldn't need much in the way of gaskets either.

If you're chasing 400 flywheel HP all you need is a cammed 5.3, no need for forced induction. My Z28 puts 425hp to the wheels with the cam stated earlier and an LS6 intake.

 

[Supercharged111]

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I've gotta say that that video proves nothing. The valve events of the LS6 cam are such that drivability is still good, albeit at the expense of low end torque which is all that I saw. We have a 2007 Envoy Denali with the 5.3 and 4L60 and it is an absolute TURD for low end torque. It's smooth as silk, holds OD great once you're rolling, but off the line the thing is worthless until you hit 3000 RPM. Then it gets its nuts kicked when it grabs 2nd gear. It really needs a 6L80 swap to shine. I have an LS6 in my C5Z and I wouldn't dream of trading it for a 350 or a 383. If you're going to LS swap don't lie to yourself, they have zero low end torque. Enjoy them for what they are and don't make them out to be something they're not.

 

[0xDEADBEEF]

I've gotta say that that video proves nothing. The valve events of the LS6 cam are such that drivability is still good, albeit at the expense of low end torque which is all that I saw. We have a 2007 Envoy Denali with the 5.3 and 4L60 and it is an absolute TURD for low end torque. It's smooth as silk, holds OD great once you're rolling, but off the line the thing is worthless until you hit 3000 RPM. Then it gets its nuts kicked when it grabs 2nd gear. It really needs a 6L80 swap to shine. I have an LS6 in my C5Z and I wouldn't dream of trading it for a 350 or a 383. If you're going to LS swap don't lie to yourself, they have zero low end torque. Enjoy them for what they are and don't make them out to be something they're not.

It proves drivability is quite good. Normal driving requires very little throttle input.

It's all about weight to power. The truck is less than 4k lbs.

 

[Supercharged111]

It proves drivability is quite good. Normal driving requires very little throttle input.

It's all about weight to power. The truck is less than 4k lbs.

Nobody will argue driveability especially with a stock cam. Nobody is arguing that an LS can't putt putt around town either. They just don't get off the line hard when asked to, and to some that is important. With a single cab, short bed, 2wd that issue is not as exacerbated.