oil and weight for 69 Firebird

[Rhymingmechanic]

James408,

Check out the Performance Years tech forum if you haven't found it already. It's a great source of Pontiac information--street, racing, and restoration. Quite a few members are from Texas.

http://forums.performanceyears.com/6/ubb.x

 

[JohnBrowning]

If you use nonsynthetic I would run Delo 400 in 15W40 with the CI-4+ rateing on the back of the jug. If you want a synthetic I would use Mobil 1 Truck and SUV 5W40 or Delvac-1. Once the Mobil 1 Extended Performance 10w40 comes online it would also be a viable option. The Delo 15W40 CI-4+ is going to have a better base stock,viscosity improvers and additive package then any 20W50 PCMO includeing VR1! I am guessing you change your oil freq. as in less then 3000 miles more then 1500 miles so synthetic is really a waste and is not going to do much for you.

I would do a used oil analysis on it and see how valvetrain wear is. If it is fine with a HDEO I would leave it alone. If it is a problem SX-UP is designed to add antiwear additives to todays oil primarly for old school high came lobe load engines!

 

[dustyjoe1]

I have a 71 lemans with a 350, not nearly the fire breather you have, but its certainly no slouch(the ol powerglide is awesome for cruising though) . It is really partial to chevron/havoline 10w40. It works fine with 20w50 also, but it responds better with the 10w40. I think I'll join the chorus thought in your application and go the HDEO route.

Nice ride by the way.

 

[James408]

Hey Rmechanic, I have visited the post at performance years. They advised that a 10w40 or 15w40 would be ok, but seemed to side with the 20w50 for hard use or racing. Any more thoughts.

I would like to maybe try the Delo 400 15w40. I have seen some negative posts on Royal Purple. I don't know how scientific they are. Will the Delo 15w40 hold up for my application?

 

[James408]

Hey Dusty Joe, thanks for the compliment. I hope to post a picture of my ride soon.

 

[James408]

Another consideration on oil. With the cam and carb, the Holley runs a little on the rich side. Do I need to consider fuel dilution when picking oil weight? I alway run a carb a little rich versus too lean(burning pistons).

 

[99]

Run the best filter money can buy and dump the oil monthly.