Hello!
First off, I want to preface by saying that what you ultimately decide to take and when is completely up to you; I am just going to advise you based on what I know and what I have experienced. And as always, consult others, including your advisor/the pre-med advisors, if you want multiple opinions.
I have been contemplating the two options for some time now, and I have to say that I think neither option is necessarily worse than the other because most premed requirements are all pretty daunting combinations. The only semester combo most people insist on avoiding is biochem and pchem. I really don’t know anything about the new Physics courses since they just changed them, but I know you also have to take a lab (PHYS 251) along with PHYS 250. Since that is the case, I would definitely suggest taking CHEM 230 and PHYS 250 together because you definitely do not want to have to deal with the stress of an orgo and physics lab in the same semester (unless you are a physics person. I am not, so it is probably just my bias).
I also don’t know if you already have taken 2 semesters of BIO lab, but a lot of students usually take BIO 226 along with 225 to fulfill the BIO lab requirement. If this is the case, then having two labs in a semester is going to be unavoidable, but I personally would still advise separating CHEM 216 and PHYS 251. BIO 226 was probably my favorite lab I took at Michigan, so if you do have to take another semester of BIO lab, I would suggest that one.
As for CHEM 230 versus 260, I took 230 with Gottfried and really loved it. She is such an awesome professor, so I would highly recommend taking 230 with her. I don’t know much about 260 other than the topics have a slightly different focus. I believe it is considered the engineering version of 230, so if you are premed, I would suggest just sticking with 230 unless you have a particular interest in quantum, etc. I checked the LSA course guide, and it looks like the median grade for 230 is a B+ while 260 is an A-. More about the course/topics covered is also there, including this: “Students who plan to continue beyond a fourth term in Chemistry would typically enroll in CHEM 260/241/242 instead of CHEM 230.” Not sure if that applies to you but thought I’d throw it out there.
Again, seek multiple opinions if you still feel unsure, but I don’t think you can go wrong. As I said, premed courses are generally tough all around, so just be prepared to dedicate yourself no matter what you choose.
Good luck, and feel free to reach out with more questions anytime!
 
-Nick
PMH Advisor