The piston on the top left is from an 01 LQ4 6.0L, the piston on the top right is from a later model 5.3L, and enthusiasts will recognize the piston on the rod in the middle is from an '02 5.7L ls1. If I had an extra LS3 piston to put here you would see it is even larger than the LQ4 piston and flat top like the LS1 piston.

This isn't the best photo for what I'm trying to illustrate but what I'm trying to illustrate is, The actual size difference between the pistons of our favorite power plants and how there is truly no replacement for displacement without a power adder of some sort, You can only turn so much more RPM to get the work with less displacement and all the LS engines are basically limited to the same RPM so you might as well buy the biggest pistons in the catalog if you're spending money on Pistons right? hell if you're spending money on pistons you might actually spend less money on a complete running junkyard long block of a larger size than what you are trying to fix up?

What I hope you should glean from this photo is, if you are considering camming a smaller displacement engine or rebuilding it and You are set on spending money on new pistons You may want to consider just getting a different short block so you can get larger pistons because The budget pistons all basically cost about the same and so if you've already set to spend money on Pistons it's not that much more to find a larger block anyway and at that point you may be able to just find a larger short block for what you were going to spend on rebuilding the smaller one anyway get where I'm going with this?

Here's more pictures of ugly pistons, still the LQ4 on the top left and the LM7 on the top right both the Pistons on the bottom are 5.7L, 97' on the left and 02' on the right.

You can see better here the massive size discrepancy between the 6.0 and the 5.3 multiply either of those pistons by 8 and you can see why 6.0 commands such a premium when it's assembled and running. Although both engines cost exactly the same to rebuild don't forget that so if you are considering putting something together or fixing something up for torque and street fun I strongly suggest looking for the largest thing you can find so you don't have to be disappointed and want to do it twice because you know you left some torque on the table.

I'm not hating on the smaller engines here at all I love the 4.8L in fact I always agree the 4.8 is the best first swap candidate because it's the cheapest to get to complete You should get as complete a used unopened and smooth running little Ls engine as you can, buy the clean but little motor nobody wants with the computer and all the controls still on it Don't forget the drive-by wire pedal if it's a newer model yards like to forget that, Guess what though the 4.8 comes with the same intake and fuel injectors and exhaust manifolds as the 6.0 and the 4.8 cylinder heads are an upgrade for the 6.0 so make the swap as simple as possible and even make sure that your first set of upgraded heads are in good working order when you sort the chassis, put the complete 4.8 in your vehicle and get it running perfectly with all the accessories and stock components still on it and get your swap running tip top in every other regard to drive ability and NVH with the 4.8 Don't worry about how slow it is, just make sure it drives turns and stops as it should then, just build your dream LS engine on the stand in your spare time for pennies because it costs exactly the same to rebuild the big motor as it does the little motor that you're using though your getting great gas mileage with it as a placeholder for your big dream LS, That's the way to do it, by the time it's ready your swap will be ready and sorted driving turning and stopping nice and it will be a simple long block switch because you already did all the hard work with the motor mounts and plumbing the intake fuel and exhaust when you swapped in the already running 4.8L. That's my general thought on these things these days If you want to go faster reasonably responsibly and cheaply without a lot of headaches.

 

The only replacement for displacement is twin turbos

 

Fixed for you

 

That was a long post just to tell us what we’ve already known for generations lol.