China can't win a military victory. It's a stalemate, and will be for a very long time. Chiang's strategy was to wait until the Allies were in a war with Japan, which is what happened IOTL. Unfortunately, he never planned on them doing so bad in 1942 and letting Burma be occupied and cut Japan off from aide, which is what really hurt the Chinese war effort.
In this case, he never gets what he wants, but that may actually be a good thing for Chiang Kai Shek. However, we are still looking at many more years of stalemate.
No Pearl Harbor means the following will happen.
The first American Volunteer Group (Flying Tigers) will be supplemented with a second group of bombers by start of 1942, and will be joined by a third group - this one of fighters again - by mid 1942.
China will start receiving very basic supplies - rifles, ammunition, uniforms, etc. - and equipment to improve China's logistics and transportation network. But it will be a very long time before this leads to any substantial improvement of the Nationalist Chinese Army.
Because Burma will never be conquered, China will benefit from not having to have forces defending Yunnan from Burma, and Chiang will never lose the services of some of his best divisions in Burma, which happened due to a combination of heavy losses and "X Force" being cut off in India.
The open supply route with Burma will allow any additional economic aide to be used to buy needed materials instead of fueling inflation.
The Burma-Yunnan Railway will be completed sometime in 1943 and increase the supplies able to be sent to the Nationalists.
With these improvements, the performance of the Nationalist armies will not degrade like they did from 1942-1944. This is probably enough to maintain the stalemate which they did in 1942-1943. It's probably also enough to prevent a disaster like the Ichi-Go Operation in 1944.
Despite this, the Nationalist Army is still a long way away from conducting a successful offensive operation. If they do, it'll be centered in the south towards the port of Canton. This is where Li Zongren wanted to attack in 1943, and where the Chinese did attack in 1945 after a substantial upgrade of forces after the Ledo Road was opened. Since the Chinese are likely to remain a low priority, they won't receive all the Lend Lease they lack, but they might be able to take Canton on their own sometime between 1945-1947. It'll be bloody though.
By this time, the war in Europe is over. Japan's aggression will seem very out of place in the world the Allies/United Nations intend to build. They can dump all sorts of excess war supplies and Lend Lease to China now. The US and British navies can concentrate on the Pacific. France will be very adamant that Japan return Indochina to it and withdraw all troops.
At this point, it's likely the Allies will force Japan into a negotiated peace. At the very lease, Japan will need to leave Indochina to avoid war. The most likely scenario is that Japan pulls back its forces from China, but keeps Manchukuo and its direct colonial empire. Japan seethes in at the humiliation and plans revenge. Of course, depending on how crazy the Japanese are, it might explode into a war, in which case Japan is quickly bootstomped.
The war is over before China is able to push Japan out by itself, but it's possible China might be able to score a few noticeable victories in the south and liberate Canton. If for some strange reason, the war isn't over by then, it'll take many more years before China is able to push on and retake Nanking and Shanghai. Even more before it crosses the Yellow River and retakes the North China Plain. All of this is only possible if the US continues to supply Chiang massively. But I honestly can't see this happening without some kind of diplomatic solution, or an expansion of the war occuring first.