GPI - L83 Drop-In Piston / Connecting Rod Package
Bulletproofing the L83 for Boost
The LT series GM engines are incredible powerplants as designed – however unlike their predecessor (LSx) – the LT’s commonly rebel when power adders such as superchargers, turbos, and nitrous are added.

unlike the LS – the LT’s commonly rebel when power adders such as superchargers, turbos, and nitrous are added.
The LT powerplants have several weak links when boosted:
- the unique piston and ring land design which was intended for naturally aspirated duty is subject to failure under even minimal detonation.
- preignition has been associated with various detergents found in certain motor oils which become emulsified resultant of the fuel being sprayed under pressure into the cylinder creating unintended combustion
- We have found ring end gaps as small as .008 which will certainly butt together causing cylinder, piston and ring failures when subjected to increased heat and cylinder pressure.
- We have found L83 connecting rods during engine upgrades on stock forced induction engines which were slightly bent even though they were still asymptomatic.
Overcoming Limitations
Understanding these limitations – and because GPI strives to provide the best combination of power and reliability for our clients – we have worked with Diamond Racing and Callies to offer a no rebalance, standard bore, stock compression, drop-in solution for the Gen V 5.3 liter L83 engine.



What does this mean for you? No machine work and no balancing needed. This is a complete drop-in assembly that can be installed while the engine is still in the car!
The Solution
Gwatney Performance is proud to present a Complete Drop-In Piston and Rod solution for the Gen V L83 (5.3L) Engine! This package is designed specifically for boosted 14+ Silverado / Sierra / Tahoe / Yukon.
By working directly with Diamond Racing and Callies, and were able to get the exact same bobweight as the factory piston / rod assembly, and due to the heavier weight of the factory assembly – we were able to build an extremely robust piston and rod package.



This kit is designed to support 900+HP applications and is the perfect match for your forced induction L83!!
Results?
Reliable and consistent high horsepower Gen 5’s! Here is a recent build with these our very popular Gen 5 LT pistons. This is a street car, so power and boost levels are fairly conservative.
- GPI LT Drop In Pistons & Rods
- GPI LT Cylinder Heads
- GPI LT Camshaft (SS1)
- G1Pro Sheet Metal Intake Manifold w/ GPI Port Fuel Injection System
Questions?
Give us a call at (501) 985-4947 or email [email protected]
To apply for a dealer wholesale account – visit our GPI Dealer Application Page.
Evan (verified owner) –
Took awhile to get here but product is good
David Zepeda (verified owner) –
Very Happy with all the pistons, rods, bearings! Best bang for your buck! I’m building an l83 with a magnuson supercharger in my 71 C10! Definitely putting this to the test!
Mike Mangold (verified owner) –
Wow, this company went above and beyond my expectations! Super nice, very knowledgeable, I definitely recommend GPI and look forward to sending in my heads to y’all ASAP!
Anonymous (verified owner) –
Couldn’t be any happier came faster than I thought and glad I listen to all my turbo truck friends guiding me they say they love them besides the quality the price is amazing if I build another gen v these will be the brand to go with without a doubt