LM7 HELPFUL HINTS

[Bryan Fagan]

Hi everyone,
I found a donor truck for my engine swap and I was wondering if there were any opinions on the LM7 5.3. I have read here on the forum and I am taking the advice on getting everything transferred to the truck and then working on mods and updates as I go. Just curious if there were any helpful hints on do's and don'ts of the LS swap on my project. Please and thank you!

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[Jermaine Smith]

Replace the lifters... dont buy the cheapest lifters on the market. You'll thank me later

 

[L31MaxExpress]

Get a 6.0L or bigger.

 

[Schurkey]

There's no way "I" would go through that much work and that much effort and expense...to install a 5.3.

Even worse, there's a guy on the forums looking for help to install a 4.8L. I can't imagine.
https://www.gmt400.com/threads/help-needed-asap-99-4-8-in-94-c1500.49174/#post-1100280

The only way any of that makes sense if if there's plans for a turbo or blower or something; and that's way beyond my pay grade.

 

[stutaeng]

Hi everyone,
I found a donor truck for my engine swap and I was wondering if there were any opinions on the LM7 5.3. I have read here on the forum and I am taking the advice on getting everything transferred to the truck and then working on mods and updates as I go. Just curious if there were any helpful hints on do's and don'ts of the LS swap on my project. Please and thank you!

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Nothing wrong with the 5.3, it just likes to spin faster. The 5.7 makes more torque at a lower RPM and slight better fuel economy for the 5.3. Is your truck a regular cab? 5.3 should be pretty fun in a RCSB. Finding parts for the 5.3 will be easier down the road. 5.7s are not as common as they once were here in my area.

You can do a 0411 swap/upgrade and that will control the new engine or you can get the new harness from donor and re-wire your dash with the new computer. I believe everything will work. '99-02' are drive by cable and '03+ will be drive by wire, so you will need to swap pedal and module. Not sure if GMT400 and GMT800 pedal assemblies are the same, but I'm sure it could be adapted.

I've got a 4.3/4L60/3.42 ECSB '99 Silverado. Engine is worn out and transmission needs new valve body. I'm going to swap in a 5.3, but also want to do a 4L80, while I'm there. Just like the smooth 4L80 more, but that involves some minor fabrication, some minor rewiring and a shortened driveshaft. If you haven't thought about it, consider regear to 3.73 or 4.10 and that combination should be pretty sweet.

And what's wrong with the donor truck? Doesn't seem like it's wrecked or anything?

 

[Idle Serge]

I got the 5.3 - the PO did it all, mated with the NV3500, TX Speed Cam, LS6 springs and flowmaster 10s. Doing pretty well thus far. Averaging 16 mpg, mainly city driving.

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2020-07-01_08-47-35 by Sergio Zapien, on Flickr