Quadstar Tuning LLC

"My absolute favorite business to buy 6.5 parts from. Great service and super quick responses to help inquiries. Purchased a tune a couple months ago; the whole process was easy and fast. Great experience!"

"Fantastic company! The best source for upgrades and performance parts for GM’s 6.5 diesel engine. Parts quality is excellent and product support is second to none!"

"Awesome customer service. I ordered a tuning chip for my 6.5 turbo diesel. I actually made a mistake when I ordered it. I was able to send it back and get it corrected. They were nice enough to pay the shipping even though it was my mistake. I've never had customer service like that before!"

"Quadstar tuning is the only place to buy high quality parts for a fair price. The Quadstar team has helped me even before I spent money with them! Since my first order from them I was hooked! The parts are high quality, well engineered and you can see the passion in the quality! I have many parts from them and they have made my truck what no other company could do! The best part is this is a small company that is passionate about what they do, their reputation is held in high regard! If you have a problem they are there to help correct it! I work on these trucks and can not praise them enough!"

"These guys are LEGIT!!! Like many, I’ve had my struggles trying to maintain and restore a 6.5 diesel motor in a 94’ Chevy. It can be quite the task…. But these guys have some of the hardest to find parts, great customer service, and superior knowledge about these engines. Don't hesitate to buy from them."