So as mentioned my engine is going to need bored out, and new pistons to go with it. I have it narrowed down to ordering some nice higher compression pistons to rectify one of the Olds’ biggest problem of a 7.9:1 CR. Might as well since I am spending the money. The question is that only one part number is listed, but two compression ratios. How do I determine what I am actually getting as well as what to order?

https://www.uempistons.com/index.php?main_page=product_piston_info&cPath=3_4_23&products_id=2875&zenid=f8345ff3befce673401df184b2b7df65

Of specific mention: listed is both 83CC as well as 96CC, with matching expected CR. I would love to go to 9.5:1 but have no idea how to achieve that. I would like to order these so I can get the ball rolling.

Trans am convertible for your time.