r/22re

I got a quote to fix my original Toyota radiator on my 91 4Runner. The ol girl has 267k miles on the clock, and at that price I could get a new CSF unit. I've heard mixed reviews for the CSF rads, and I saw Spectra Premium has a brass tank coppor core unit on Rock Auto. Should I just get a plastic/aluminium unit instead? I'm kinda lost on how to go about it and some insight would be much appreciated! (22re engine)

https://preview.redd.it/w0ow728f1qzg1.jpg?width=3000&format=pjpg&auto=webp&s=a711b48ccd75a78e343e0391c3e7501895e35f81

I have an oil leak and have noticed a new rattle, I think its becuase I let my oil level get too low and it affects oil pressure and in turn chain tension. When I ran some lucas oil this morning it was much better although once hot it did rattle again. Looking at these marks on the head, it looks like the PO had slap but replaced the guide as the marks are behing the plastic guide as well