5.3 litre computer mods.

[Fenny]

Hey guys. I am new to this forum and have been browsing around looking for info on 4.8,5.3, 6.0 litre install some of the people on the forum have done or are in the process of doing. I have a 5.3 and a 4l60e that I am planning to install. What I am wondering is what can be deleted from the ecm? Any info you can give me would be great. Thanks.

[saulgoode]

This would be a good place to start looking.


And welcome to the board

Saulgoode

[69Custom]

Here is my latest pic of what it looks like. Moved battery to driver's side like the newer trucks. For you computer go to LS1truck.com and Nelson Performance can change whatever you want. There are others out there too.

[Fenny]

Thanks for the tips guys. 69custom did you remove the O2 sensor?

[68LSS1]

Not exactly sure on the trucks but on the F and Y body's and for hybrid's you can delete the rear O2's as they are for emissions. The forward O2's are for fuel management. You could delete them and run in closed loop all the time but this will take some special programming and not be cheap as it could take multiple programs to get right.

[FirstGen]

You will have to delete rear O2's with any gen III based swap unless you plan to run cats with your exhaust. You will also have to delete VATS for the motor to start. At this point you will probably want to delete any emissions equiptment on your particular year motor... Personally I would stay away from a mail order tune like Nelson because your combo will only get the most power from a dyno tune with a wideband. Any good large performance shop should have this capability and be the same price...

[69Custom]

As like the others said, delete emissions. As for tune I got a price at a local shop here and they wanted $650 for it and I paid $425 for a complete performance tune. It is all a matter of opinion. Good luck.

[FirstGen]

well 650 is a rip off. I paid $400 and that is one of the higher prices in Dallas.

[gmc67swb]

I think AMS is $400 for the complete tune. My buddy got a cam installed at the new shop on Peachtree( I think Fasttech), and the tune was $200. They made quiet a few pulls that day. The car put down 540hp to the wheels when all was said and done.

[oldsub86]

A tip for the Canadian guys - or the rest of you if you want to come north for a roadtrip. Princess Auto has some new 4.8's sitting around. There is one on display in the Panet Road store here in Winnipeg. The tag says about $2K but I have it on good authority that you can probably get one for about 1/2 of that. It appears to be a complete motor right down to the spark plugs.
You would need the rest of the stuff to make it work if you want to drop it into a 68 - like computer and harness etc.

[Fenny]

Thanks again guys. I found a shop here in Calgary that will reprogram my ECM for $350 cdn. I have one last question reguarding the wiring harness. I have the stock harness out of the truck that I bought the engine from. I only have the engine harness. Will I need the fuse block as well? I currently have a painless replacement.

Thanks

[68LSS1]

You shouldn't. I'm not familiar with exactly how Painless does there harnesses but most the aftermarket harnesses will require about four or five wires to be hooked up. Did they include a fuel pump relay in the harness? If they didn't maybe a couple more.

[incoma]

Speartech will add a fuel pump relay/harness, and add extra wire if you want to move the ecm into the cab. Its been a few months since I talked to them about their services. I think they rework a stock wiring harness for about $450. I've heard good things about them from other LS1 hybrids. I guess the other option is to buy a wiring diagram for your engine and just adjust the harness for your appl. Sounds easy enough right??