If you search the posts on this site I think you will find several discussions about
oil thermostats. That is what I did and decided to go with the Canton Racing unit. As I recall, it was the only one that seemed to work!
It's a lot of work to install,or at least it was for me. I have the remote
oil filter, so this added lots of braided stainless tubing and AN fittings. My
oil temperature still tends to run low, but this unit keeps it much warmer, I'm convinced.
If you don't intend to race your car, you should consider dummying up the oil lines to the oil cooler. Your engine will be much happier, I expect.
Hal