which oil would you use?

I am going to the change oil because the oil I use has no zinc in it. I have a 1971 Demon 340 with 6000 miles on the motor.Not sure which to use. This may have been talked about before but I am new to Moparts. Thanks Greg

You're gonna get many different answers.

I run 15-40 heavy duty diesel oils such as Shell Rotella T, Delo and the NAPA brand. I've had my valve covers and oil pan off a few times over the past 10 years and the engine is clean. The oil stands up very well. Zinc levels range from 1000 to 1200 ppm in todays heavy duty oils. This level of zinc is all that is needed for stock or mild builds. Racing oils are more in the 1300 ppm zinc range.

Thanks you I was told to make sure that the oil I used had zinc but wanted the opinion of others so
I didnt get ripped off when I go to buy th oil.

GREG

There are lots of alternatives. Diesel engine oil + STP has worked well for me on a moderatly aggressive mechanical flat tappet. The STP bumps the zinc level up a bit and may have other benefits.

Welcome to moparts.

Moparts thread 1.

Moparts thread 2.

Here's another one to read.

...I was going to run the Rotella T (none synthetic) like the previous owner of my Diesel 3500 suggested & a lot on Moparts too, until I read this completely through.

http://docs.google.com/viewer?a=v&q=...o-95B2QrXOiWmNA

I switched over to synthetic oil about 5 years ago. After looking around on this site, http://www.bobistheoilguy.com/forums/ubbthreads.php I saw that the Mobil 1 15W-50 had a very good Zinc content, so I switched to that this summer. The other versions of Mobil 1 were OK, but the 15W-50 has about 1350 PPM Zinc - higher than a lot of the diesel oils they tested. I was using the Quaker State Horsepower 10W-30, but that's only in the 900s PPM Zinc - not enough. I don't leak or burn oil, and my engine is well broken in, so the cost of synthetic over conventional isn't an issue for me as long as the synthetic has the properties I'm looking for.

The next engine I build will be roller cammed, so it won't matter so much then...

Quote:

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...I was going to run the Rotella T (none synthetic) like the previous owner of my Diesel 3500 suggested & a lot on Moparts too, until I read this completely through.

http://docs.google.com/viewer?a=v&q=...o-95B2QrXOiWmNA

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Good info, but probably wasted on a lot of people. I think it's a bit outdated now.