ST185 valve springs in ST165

I'm replacing a single valve spring in my 165 and I got an MR2 turbo valve spring, but it seems to be bigger and I don't know if I can use the circular piece that goes on top of the spring and fit the bucket on it. Should I just fit the valve keepers on anyway?

The Toyota part number for the valve spring you need is 90501-32022. In the USDM, that valve spring part number is unique to the ST165 only.

It appears that part number is still available through Toyota dealers:

- https://www.toyotapartsdeal.com/oem/toy ... 32022.html

If it is indeed still available to purchase, I would highly discourage you from tying to fit something not meant for that engine - especially in critical areas like valves.