[8453johng]

I just finished rebuilding the engine and transmission.

I have put about 50 miles on with the break in oil in the engine.

Chasing down gremlins in the car. What Fun?

Can someone recommend the oil to use in the engine after break in?

[78w72]

Youre gonna get all kinds of varying opinions on oil in here... but if its a stock or close to smaller cam, after full break in you do not need any of the expensive specialty race oils or ones with super high zddp (zinc) levels. Modern oils are backwards compatible with previous API grades and have other modern anti wear additives to compensate for lower zinc levels.

I have used good brand off the shelf normal oils for almost 30 years in my 1981 301t pace car with zero issues to the cam/lifters, same for a bigger .480 lift cam in a 78 400 for about 20 years... & another 455 in a 78 TA when I was younger for 80-100k very hard miles. To me thats proof that normal oils are perfectly fine for most of these stock to mild cam street engines.
Oh, and my last daily driver that was a Jeep 4.0 I put 100k+ miles on for almost 20 years, towing, long change intervals etc, has a FT cam about the same size as a stock 301 or other mid 70s pontiac V8... used the cheapest on sale oil I could find or usually walmart supertech, which is a very good oil. Zero oil related problems, sold it to a local guy 5 years ago with 200k+miles... still see it driving around town today.

Thats being said there is nothing wrong with using $10 or more per qt special "hot rod" or racing oils, but they are just not needed, especially for cars with stock engines or rebuilt smaller cams after fully broken in.

Lots of myths & hype on the internet about oil or zddp, some on here or out there think you need a racing specialty oil & then even add more zddp additive to it for their small or stock cam street engines. Your choice on what you use but in my experience a good normal oil works fine in these engines, I like valvoline max life or other high mile oils since they usually are a little more robust and higher in zinc or moly etc & will help keep gaskets & seals in good shape, especially on higher mile engines.

For the trans, good idea to change the ATF & filter after about 500 miles, again, any decent brand dex3 rated ATF is fine... I use supertech or maxlife ATF in my stock 1981 TH350 trans as well as a street/strip TCI TH400 behind a 500+ hp stroked Pontiac that does low 11's, works great with firm shifts after 10+ years.

Just my real life experience owning & maintaining Pontiacs & other FT cam vehicles for a few decades.

[burd]

Look in your owners manual.

[78w72]

Owners manual is 45+ years old and only shows weight or 40+ year old API... doesnt recommend a current oil to use which is what hes asking.

Bottom line, you dont need specialty/racing oils for these stock or smaller cams once broken in... but they can be used without any problems or if it helps you sleep at night.

[78w72]

Originally Posted by 8453johng

I just finished rebuilding the engine and transmission.

I have put about 50 miles on with the break in oil in the engine.

Chasing down gremlins in the car. What Fun?

Can someone recommend the oil to use in the engine after break in?

10/30 or 10/40, the rest is your choice of brand/type.