Difference between a 4.8 and 5.3 ls engine

[structures]

So I was browsing Craigslist last year and found an advertisement for a 5.3 4l60e combo. It had been pulled out of a 2006 roll-over and the truck was gone. I had no VIN or any documentation to tell what it was. I bought it though because the engine cranked over great and the compression was good. Well as time went on I cleaned the engine up and noticed something sticking out from the head gasket. A little flange with 4.8 stamped into it. My heart sank. Well sure enough I pulled the oil pan and checked the casting on the crankshaft. I had a 4.8 on my hands. I'm happy with the 4.8, I just want to list a few of my observations to maybe help others identify what engine they have. And hopefully others can chime in with observations as well for other eras of LS engines.

Of course if you just aren't sure about the engine, pull the oil pan and internal baffling and check the crank. It's not that hard and you can easily see the crank casting number.


So first is the picture of a tab coming off of the head gasket. This tab was on both sides of my engine. Stamped on the tab is 4.8.



Here is a closer shot of the tab.



Something I noticed later and I can't verify now (b/c I painted over the block) is a green paint mark over the 4.8 block casting. This picture is from the front of the engine.



Although when I was looking back in my photos and looked at a picture of the backside it almost looks like the 5.3 is highlighted. So I don't know how reliable the green paint is. Maybe others can verify.

[dwcsr]

I had the same thing happen to me , was supposed to be a 04 5.3 80k miles ended up with a 4.8 00 with 225k. I'll have to look on my old gaskets to see if it says 4.8. I don't think it had tabs

[78bronzechariot]

I bought the one I put in my truck knowing it was a 4.8/4l60e, and I absolutely love it. They are only about 20-25 horse less than the 5.3 and and about 35-40 ft-lbs less torque. I recently drove mine to Chicago to help my Aunt move. I had the 8 ft bed loaded with a mahogany bed set and end tables, and a bunch of odds and ends, certainly a full load of 1000 lbs or more. According to the "seat of your pants" dyno it seemed almost as quick as when it was empty. I also had to get on the interstate at a cloverleaf interchange while it was fully loaded, I had no problem and plenty of pedal left merging it into 70 mph traffic in the 1/8-1/4 mile window you have on a cloverleaf. If you don't plan on making 500 horsepower, I don't think you have reason to worry, other than bench racing with other board members . In the end, I couldn't be happier with it, 21 mpg on my trip to and from Chicago, and cruised it a 70 the whole way there and back.

[Critter]

My 6.0 and Jtrux's 6.0 (that is sitting in my garage) both have "6.0L" stamped on the back. Do the 4.8s have 5.3 stamped on them or something? Structures what do you mean by "highlighted" in the first post? I haven't looked into buying a 4.8 or 5.3 but I want to know what's going on when I need to go searching.

[structures]

Just like your block has 6.0 casted into it. The 4.8 and 5.3 use the same block so both numbers are casted by each other (4.8/5.3). Unfortunatley I didn't take good photos of the green paint which seems to cover the casting number. It wasn't until I was looking back at old photos that I noticed the green paint.

I got to thinking maybe that spot of green paint was covering the 4.8 which was an external way of signifying I have a 4.8 engine.

[Critter]

Ahh, I was expecting something like that when I asked the question, definitely good info to know. Thanks!

[Kabwe]

The 4.8 has flat top pistons and the 5.3 has dished. My block did not have the 4.8 or the 5.3 highlighted so I had to look at the pistons. A HO 5.3, it will have flat tops, but the block is also aluminum.

[mcbassin]

I did the same thing, found a nicely priced "5.3" only to find out when I got home it was really a 4.8. This was how I figured it out HERE Not that big of a deal to me it will get used in one of my many projects.

[structures]

I also found out mine was a 2007 and up instead of an 06. It took 3 oil filters before I figured out that the engine I had, used the newer metric threads. The 4.8 is a good engine, my dad's truck has one in it, but I'll never buy another engine off craigslist unless I actually get to see the truck it's coming out of. It's not that I don't like the 4.8 but when you buy something, you want what's advertised. Also I passed up a lot of good deals for the 4.8 4l60e combo because I was looking for a 5.3 4l60e combo without 4 wheel drive.

[dwcsr]

I paid just at core for the engine and trans so I'm not so worried about it being 4.8 and not a 5.3, I have to rebuild it and scrounged 5.3 parts. I got a 10/10 crank for $55, some flat tops for an 05 for $160 and a set of new rods for $200, new cam for $70 and lifters for $90. So far I'm ahead on the rebuild.

[Jim_PA]

It's like the whole "yup, it's a 350!!" thing all over again.

[mcbassin]

Originally Posted by Jim_PA

It's like the whole "yup, it's a 350!!" thing all over again.

I understand this one. It used to be "yup it's a 4 bolt main 350" all the time.

[djw32]

Here is the best link to tell the difference between a 4.8 and 5.3.

http://www.pera.org/articles/eb120317.htm