I am going to do a oil change. And therefore I wonder whats the best oil to get for my 69 Cutlass conv. 350 engine? It has been rebuilt and hardened seats. In the oldsgroup of google is a discussion going on about zinc in oil. So it came to my mind before I do the change job.

 

I've heard the diesel oil Rotella T is a good oil to use. It is supposed to cut down on all of the sludge build up in an engine if used consistently.

 

Unfortunately, Rotella and the other diesel oils are also going through a zinc reduction. There are now vendors selling both additives and motor oil that puts it back in for older cars.

 

I use Rotella 15/40 in everything I own.

 

You can order cam break in lube that contains enough zinc additive from summitracing.com that you can add to any oil. Competition cams part # CCA-159. $10.25 per bottle. Add one per oil change and get the proper zinc you need for your flat-tappet camshaft.

 

if your engine is not new and is broke in, all you need to do is go with a good brand. the lower zink is bad for breakin but other than that you will be fine. that is also if you don't have a extra high lift cam. but i will agree that rotella t will be fine to use and it does have more zink than gas oils.