I need to clean my valve covers which are aluminum. They have some oxidation on them. Tried some mothers Aluminum Polish and hand cloth but after scrubbing and area 3x not doing the job. It did make an improvement but want them looking better. Want to do valve covers, chiller, blower and intake monifold. Any suggestions on what product and method of polishing works best?

To get them looking new again, you need to put them on a buffer. You need some good buffing pads. Not the cheap ones from Sears and Harbor Freight, but some real ones. Your best bet is to send them out for polishing. It should not be that bad to touch up something that was once polished. That's not the same as starting from scratch. You could buy a buffer and do it yourself, but it is some messy work. Try looking online for good buffers and rouge.
Eddie