what oil for 1980 350 chevy 3/4 ton 4x4

[DaleAxl]

Ok here goes. I have just purchased an 80 chevy 3/4 ton 4x4 pickup with about 130,000 miles. All my vehicles are newer with roller lifters and use Mobil 1 synthetic. However, this 350 is older with flat tappetlifters. What oil would be good to use? Here in IA temps range from -1d to +100. 10w30 is good in winter with 10w40 or 20w50 in summer. Will running synthetic oil possobly cause leaks to start? I have heard rottela 5w40 synthetic. Won't cause these leaks, but I'm not posotive. Running a dino oil is no problem, but I desire an oil or even an additive that would be benificial to flat tapprts.

 

[DaleAxl]

I apoligize for misspelling and punctuation. For some reason nothing shows up on the screen of my blackberry when I ask a question so I have to poke and hope.

 

[addyguy]

Rotalla T synthetic 5W-40 all the way.

 

[jazeo]

I think you should continue to use whatever oil the truck as become accustomed to, if you can't determine that, in my opinion any HDEO in a 10w-30 would be fine. I guess I feel if it's made it 130k on dino, no need to switch at this point..

No "possible" leaks and good for flat tappets, win, win....

 

[HyperJinx]

Rotella!

 

[grease_monkey]

Rotella to the max. Used to use their strait 30 weight in my 1968 ford f 250 ranger. I got rid of the notorious lifter noise the the FE Blocks had

 

[DaleAxl]

I guess ill be using rot T6 then. Thanx guys

 

[Jaymus]

Originally Posted By: addyguy
Rotalla T synthetic 5W-40 all the way.


+1

There is a UOA on the first or second page of the gasoline UOA's for a 5.7 (350 V8) that ran Rotella 5W-40.

Couldn't have asked for better results for a 5800 mile run. TBN was still 4.8 or something. I tell ya, RTS 5W-40 is HARD to beat.

EDIT:

Scratch that. It was 6800 miles. Here's the link:
http://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1706085&gonew=1#UNREAD

 

[pavelow]

Another vote for Rotella Syn 5W40.