Well, generally his power would increase significantly. He'd likely have enhanced physical abilities like strength, speed, and stamina. His chakra reserves would also be much larger, allowing him to perform more powerful jutsus for a longer period without getting exhausted.
When Naruto absorbs the Kyuubi in the fanfiction, his power undergoes a remarkable change. His chakra becomes a blend of his own and the Kyuubi's, which is an extremely potent combination. This new chakra source not only gives him a physical edge but also an advantage in terms of strategy. With the vast amount of chakra, he can now afford to use more chakra - intensive techniques without worrying about running out. In addition, his recovery time between battles would be shorter as his body is now more resilient, thanks to the Kyuubi's influence. His newfound power would also earn him more respect among his peers and make him a more formidable force in the ninja world.