GPI Is one of the BEST performance shops around. I have been using them for performance parts for my 5th Gen and 6th Gen Camaros for the past 4 years. I could not be more pleased and happy with their camshafts, tuning, 6L80 trans bench build, and overall build advice. If you are looking for proven performance, GPI is the right place for you. They do not just dyno their products, they actually track race them and get real data. Their customer service is top notch and they will bend over backwards to make sure their customers are happy. A++

Guys were very helpful on helping decide what I needed done and compared to other places I checked you couldn’t beat the price for what was done. Truck runs better than new and got woke up some! Def the guys to go to. Very pleased all across the board.

By far the best customer service when it came to specing out a H/C/I set up for my NA 427 LS. They took the time to talk in depth and explain things and didn’t just push their parts over on me. And they always answer any stupid little question you may feel your bugging them with no problem. Very knowledgeable guys and make you feel like your are not just another purchase order number. If you want some of the best R and D out there a team to back it up I highly recommend them!

I would trust nobody else with my C6 Z06. Aaron really took the time on the phone to walk me through all the options on what the best mods would be for my goals. Extremely knowledgeable and helpful staff. Aaron, Ryan and the entire team over there are extremely nice and know what they are doing. I am extremely happy with the result of their work on my Z06. They even finished it a little earlier than quoted, which is unheard of in this business. GPI has a customer/friend for life now. This is how you are supposed to do business. Highly recommended!