Which conventional motor oil for '67 GTO

With the reduction of zddp in motor oils, what brand of 10w30 should I use in my never rebuilt 400 cu. in 2bbl Pontiac engine? I have 125,000 miles and have never had a single issue with my engine since I bought it brand new 46 years ago.    It does leak oil in a couple of locations (like the rear main) but does not burn oil. Would a high mileage oil be best. Should I add some ZDDP from Eastwood when I change oil?  

I'm using Brad Penn, no problems.
Steve  
A little help... 'cause we don't all have to learn the hard way!

I use Valvoline VR-1 and never had any problems.  
Engine builder,self taught auto body guy.
Horsepower sells engines and torque wins races

redgoat

I see your questions include one regarding high mileage oil.The high mileage oil question is actually a very difficult one to answer. MY best suggestion is to call Valvolinne tech line directly and ask them. Anyone can call and the wait time is typically less than 5 minutes. Trying to decipher the info online can be confusing and overwhelming.

Without any good high mileage engine oil info I personally would do this. Stick to what you have been using for the last many years. It’s gotten you this far. I would just go up one weight to like 15/40 etc to compensate for the natural wear of the internal parts.

The ideal amount of zddp required for old school flat tappet engines is another confusing issue. Mobil 1 says around 1100 ppm, valvoline says 1300-1400, I think joe gibbs says 1800 and lucas uses around 2800. Flip a coin.

This being said I have always used valvoline. The VR1 is an improved version of their std 40 year old oil. In your case I personally would use a slightly thicker grade of VR1 or similar in another brand.

The oil companies say too much zddp is also bad so I do not add any to the valvoline VR1.

Valvoline max life high mileage engine oil is W150 10W-40. One site says it’s a synthetic blend another says it is pure mineral base.

I would not use semi synthetic or full synthetic oil.

Another possible upgrade is using the new nano style oil filter like mobil 1 filter. I have read they filter out smaller particles. I do not know if you can use them with conventional non synthetic motor oil with zddp etc. I would ask valvoline or mobil 1 this question also. Hate to have one work so good it filtered out the zddp. The additional cost of these may not be that much compared to the potential long term benefit.

Valvoline’s tech line number is 800-832-6825  

Redgoat:

Do what you have been doing for the last 46 years, just add the ZDDP to your oil change. Don't use $8.00 a quart Joe Gibbs oil.... I would keep on keeping on....LOL...If you remember that saying...

Bob