Had an issue with my order and was missing 1 valve spring. Reached out to via email on Sunday evening. Jimmy responded within 5 minutes and had another spring out to me next day. I’m in CA and received it by Wednesday. Great service and beyond expectations handling issues on a Sunday.

Works great on my turbo setup quick response, no compressor surge, and holds vacuum cleanly at idle. Good quality for the price and easy to install. Highly recommend.

Controls boost cleanly with zero creep on my turbo setup. Solid quality for the price comes ready to install. Highly recommend.

Joel did an awesome job getting my truck dialed in. It runs and drives great, and I couldn’t be happier with how it turned out. He took the time to get everything right and made a few final adjustments to really finish it off. Great guy, knows his stuff, and I highly recommend him!

Cam kit shipped earlier than expected! Installed with no issues on my 04 2500HD with the LQ4/4L80e/4.10 and makes great power! Hauling hay like never before.

Haven't install yet but the cam and springs looks top quality. Can't wait to install and run. Shipped immediately

​Top-notch experience with Ron Holdener Performance Parts! Their customer service is absolutely wonderful—attentive, knowledgeable, and reliable. Highly recommend them to anyone looking for quality parts and outstanding service!

Product is perfect thank you

Would buy from these guys again for sure!

Super fast shipping

Came early and packaged very well, very excited to see how it performs in my drift car!

Haven't installed yet packaged very well. Can wait to install and fire it off.

Fits great and a lot nicer than a standard length AN fitting.

Great little keychain for my project car

Great customer service answering any questions will definitely be using them for my LS needs.