It amazes me that Chan was a cover artist for both Marvel and DC, replacing far superior artists. I mean, he does some good work here and there, but even at his best he's still no Neal Adams, or even Rich Buckler. His huge contribution at DC in 1975-1977, on a number of my formerly favorite titles, is largely what drove me away from DC for about 2 years. Particularly BATMAN and DETECTIVE, but also on titles like FLASH, the Superman titles, and even HOUSE OF MYSTERY. I suspect because he was fast, and cheap.

Here Chan did full art or inks on INCREDIBLE HULK covers, most issues from 210-226
https://www.mycomicshop.com/search?tid=83481&pgi=201

The Buckler/Chan ones on 212-214 I think were the best ones.
Some of Chan's solo efforts, on issues like 220 an 224 also are fairly nice.
https://comiconlinefree.com/the-incredible-hulk-1968/issue-224