Hi Walter, I am pleased to assist you. No need. Direct-fit converters are engineered to match the original equipment specifications, allowing for a straightforward installation without the need for welding. They typically utilize existing flanges and mounting points, enabling a bolt-on installation. If your vehicle is compatible with the information provided on our website, you can click the link below to order directly and take advantage of our current discounts while supplies last. I hope this helps, and enjoy shopping! https://www.carparts.com/catalytic-converter/ap-exhaust/ape645159?can=CPGG4850_CSQA_20250129

Hi Jose, I'm glad to assist you. Those two round rings as you called them are exhaust gaskets for the end connections of the catalytic converter (there is also one clamp included) for your 2017 GMC Sierra 1500 Denali 8 Cyl 5.3L. Grab our price-cut offer and click the link below to buy it today. Happy shopping! https://www.carparts.com/catalytic-converter/ap-exhaust/ape645159?can=cpje1043_CSQA_20240223

Hi Jose, thank you for reaching out. If your 2017 GMC Sierra 1500 Denali with a 5.3-liter engine has federal emissions exhaust system, then yes. You can use this link to continue ordering this part at a discounted price today: https://www.carparts.com/catalytic-converter/ap-exhaust/ape645159?can=CPAP3648_CSQA_20240219 I hope this helps. Enjoy shopping.

Hi Jerry, I'm pleased to assist you. No, this will not fit. Having an Engine Family Group number means the required converter needs to be CARB or 50-state California Legal. After checking, it turns out FGMXT06.2374 is currently not available. Contact us again if you require any other vehicle parts. Have a nice day!