Larger, but not incredibly larger. Consider that Chinese immigrants were overwhelmingly male and the number of families over here was very low. In addition, many went back to China once they'd made enough money. Chinese were an outsized portion of the workforce, but very small % of the US population. As white settlers filled the Western United States, Chinese would become a smaller and smaller portion of the workforce and population. You would also likely see much lower populations of Japanese and Filipino immigrants, as these waves were largely driven by employers searching for new sources of labor after Chinese Exclusion.
Likely, like OTL, you would see recent Chinese immigrants vastly outnumbering those who can trace their ancestry to 19th and early 20th century immigrants if national quotas are ever lifted.
One major difference would be Hawaii, assuming it's still annexed ITTL. Chinese, instead of Japanese, would be the dominant ethnic group on the islands and have a much bigger impact on the culture and language of Hawaii.
A better PoD for preventing the Chinese Exclusion Act imo would be figuring out how to reduce inter-white labor tensions. Anti-Chinese sentiment often had little to do with the amount of Chinese living in any given area. The overwhelming majority of congressmen who voted for the Act represented areas with no Chinese population. The racism and xenophobia was exacerbated by the economic anxiety and displacement that occurred in the United States during the earliest stages of industrialization. A society made of largely yeoman farmers, who could care less about competition in the labor market, was being replaced by an emerging class of white workers. But this early industrialization was driven almost entirely by the interests of capital and bosses as represented by the Republican party. Have the Democrats, or some labor party emerge victorious earlier in the post-Civil War era and improve the lot of white workers or at least direct their animosity elsewhere.