You haven't specified what brand and model of gtx 970 you bought, so I don't know how long the one you have is, but unless it's more than 410mm (16.14 inches) long, which seems unlikely, either one will fit. Recommending one between those would be easier if you listed the other components you plan to put into your rig, and anything special you're looking for in a case, but the specs indicate the Thermaltake Chaser A31 can fit a slightly taller cpu cooler than the Corsair Carbide Spec-03 (160mm vs. 157mm). Since the popular Cooler Master Hyper 212 EVO is 159mm tall, I'd suggest going with the Thermaltake case.