The best high mileage oil for a 83 280zx
 

I would like to get my oil changed on my 1983 280zx, it has 176,000 miles on it (and when cold, you can hear a valve clicking once in a while)

It should be a conventional oil that I can easily get at places like Kragen or Pep Boys.

Any suggestions would be great!

The best? hm. I'm a fan of Mobil 1 when its affordable (over $30 for a 5-quart here). I generally use Castrol CTX in mine. I'm sure purple power has one out that will be outrageously expensive...Most of it comes down to cash in your wallet. Any of the above mentioned brands can be found at pep boys, or ordered in.

how about oil viscosities?
5W-30?
10W-30?
10W-40?
20W-40?
20W-50?

It's slowly coming to be about winter time for this 175k mile car, which oil type would be the best for high a mileage engine like this? I'm in California so there's no snow.

I'm in California, and there is definitely snow.. :D

IMHO Penzoil Platinum is the best bang for the buck. If you really want the low down check out Bobistheoilguy for enough information to make your brain hurt. WalMart in the USA seems to be the cheapest place for PP. I run 5W30 myself. You want as low a first number as possible as that is the viscosity on start up - get the oil flowing ASAP.

Mobil 1 is good as well but PP tends to get better VOA numbers.

Don't get thicker oil to "fix" clicks and rattles - figure out what is wrong and fix the issues. The L28 is basicly bullet proof so really the most important thing isn't what oil you're using but that you change it regularly and throw out the old filter. It boggles my mind that someone would try to reuse an oil filter to save a few $$

Agreed with fricfrac, check out the bob. I know my head hurt with all of the things I learned! I prefer the 10-30 weight myself, but I know my girlfriend's 2012 Hyundai elantra asks for 5-20 weight. While thicker oil can mask ticking sounds, it won't fix the problem. Valve ticking? Check the clearance. Do what you can to fix what is wrong before you try to duct tape it together. ;) and yes, always change your filter. Even if you end up with an oil leak that makes you add 2 quarts a week, change the filter (and fix that leak!).

Remember the first number is the viscosity of the oil when it's not at operating temperature so you want it as low as possible to get it up to the valve train ASAP. 5W30 is fairly common and thus cheaper. You have to spend more money to get 0W30 so I usually go with the 5W30.