I have a 99 Silverado with a 4.8 Vortec V8 and I just bought an LS1 with wiring harness, computer, accessories, and 4L60E transmission. How extensive is this swap has anyone on here ever done it? What will be involved in getting this to work in my truck? As I understand if worst come to worst I can use my 4.8 computer and wiring harness but that requires that I use my 4.8 accessories on the LS1, and I really don't wanna do that! I could really use some help with this one!

 

i do know that you didnt need the 4l60e because you already have that in you truck

you might need the f-body flexplate though

 

if you want it to run correctly, invest in a nelson tune...

i wouldnt go another way...

 

You don't need the new wiring harness, nor the 4l60e if you already have an automatic. If your truck is manual then you can still use the same tranny that is alreay in it. Flexplate isn't nessecary, nor is the computer..although the PCM willl help. It's a direct replacement...pullthe old motor out and drop in the new one. If you have the LS1 oil pan still on it then the only thing you need to know is that the oil drain plug will now be on the driver side instead of dead center.

 

Are you putting the truck intake on it?

 

Do you mean intake(motor part)? Or like air intake(K&N)? I know that the air intake on the LS1 comes directly out the front but it would be easy to make or find a air intake to fit. If you mean like the actual LS1 intake then yes, I would like to use it. Wouldn't that be restrictive to put my 4.8 intake on the LS1?

 

How will things like my gauge cluster respond to this swap? And will i be able to use cruise control?

 

The LS1 intake is designed for better high RPM airflow, whereas the truck intake is designed for low-end torque. A lot of people here have swapped to an LS1/LS6 intake, and a lot will tell you to put the truck intake back on there. Depends on personal preference.

If you end up putting the truck accessories on the LS1, you will have to swap crank pullies because they are spaced differently (truck accessories are about 1/2" further from the motor than the f-body accesories).

All of your electronics should still work the same as they did before.

 

Exactly!! To add onto thunders post...

as he said if you put the truck accessories back on (including intake manifold (motor side)) Then the only thing you have to change is the crank pulley so that all the accessories line up!! If you decide to keep the LS1 you will need to use every single LS1 accessory in order for it to work!! Including the water pump, alternator, and so on. Otherwise you will have problems getting things to mate up. So really what you need to do is decide which is easier for you to do, either use ALL truck accessories (intake manifold and all engine dressup including crank pulley!) or use all LS1 accessories and you're all set All gauge cluster and electronics respond the same, although that was said to good luck keep us posted

 

will I lose power by using the truck accessories?