LM7 and 4l60E have arrived . Build thread will follow.

[BeXtreme]

So it's a 5.3. How much hp?
New, new ? Or slightly used take out? 4L60E, have heavy duty internals? Just curious I've thought about a 6.0 in my K2500.

That's a used takeout from a junkyard based on the crate and tag on it.

The LM7 is the iron block Gen 3 5.3L that was used in a bunch of trucks and SUV's(and others) from 99-2007. They vary in power, but ~290hp/315tq depending on year and application. A decent cam and tuning can help that out quite a bit. They did not have any especially heavy duty anything. The heavy duty engine would have been a 6.0L

https://www.onallcylinders.com/2018...ormance-bore-stroke-cylinder-heads-cam-specs/

 

[90gmcsierraL59]

It is a take out. LM7 and 4L60 E with104K from a wrecked 2004 Suburban. The GM spec said 270-295 horsepower. That is with factory exhaust and emissions equipment installed. We are hoping for a bit more with free flowing dual exhaust and some unneeded equipment removed. I am after reliability and better fuel mileage than the 5.7 TBI K motor.

 

[90gmcsierraL59]

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

A small collection of bugs and dirt under the intake. New knock sensors and harness installed. New intake gaskets and intake reinstalled

 

[90gmcsierraL59]

You must be registered for see images attach

My friend Adam spent today changing the LM7 water pump and doing a bunch of corrosion removal and cosmetic cleaning. The rusty idler will be replaced and he is taking the big aluminum bracket on the left side of the motor off for bead blasting.

 

[90gmcsierraL59]

You must be registered for see images attach

The Dirty Dingo AC relocation bracket arrived today to mount the 90 GMC compressor to the engine to keep from having to notch the frame
Adam said the fuel system components, the exhaust and the Dakota Digital instrument cluster have also arrived. I will be taking 6 quarts of Amsoil 5W30. a K&N oil filter, 12 quarts of Dexron Mercon VI, a set of NGK Ruthentium spark plugs and an air filter when I take the truck down on Sunday.

 

[90gmcsierraL59]

Greetings all. We took the truck down yesterday to Raleigh NC and disassembly has commenced. Pictures will follow. Further research has revealed we have an L59 motor not the LM7 we thought originally.

 

[L31MaxExpress]

Greetings all. We took the truck down yesterday to Raleigh NC and disassembly has commenced. Pictures will follow. Further research has revealed we have an L59 motor not the LM7 we thought originally.

That only means it has better injectors and the PCM is setup to add a Flex Fuel sensor. If you have E85 in your area, I would recomeend adding the sensor, the sensor is cheap if you get the later Continental style for say a 3.6L Impala. It is a good bump in power to run on E85 even with a stock engine. I find my van cheaper to operate on E85 than pump gas and it has more power. Running on E85 really helps the low-midrange torque. The vans 383 jumps from about 500 ft/lbs to 550 ft/lbs on E85, it runs smoother and it runs cooler. The exhaust tail pipe also stays much cleaner on E85.

 

[90gmcsierraL59]

We are doing an 87 octane tune. We have the whole engine harness for the engine. I assume from what you are saying we would have to buy another sensor to switch back and forth? I thought that these engines run on either?

 

[90gmcsierraL59]

You must be registered for see images attach

You must be registered for see images attach

4L60 and K motor out. L59 and 4L60E temporarily separated. My friend Adam is finishing up the engine install prep.

 

[90gmcsierraL59]

You must be registered for see images attach

You must be registered for see images attach

L59 block before and after