# Oil Recommendations



## 21553 (Sep 30, 2012)

Hello,

I have a 1966 GTO with a 1976 455 with Edelbrock Performer Heads. I am curious what oil you guys use? 

I purchased the car and the previous owner said to use Valvoline VR1 20-50W. I was wondering if I could switch to something else such as synthetic with ZDDP added or a lighter weight oil. 

Reason I am asking is it has a tremendous amount of oil pressure. Between 90-100psi at start and idle. Then it takes a very long time before it will drop after a long warm up but still will jump to 80+psi. Can I go to a synthetic or a lighter weight oil? Will this help reduce the pressure a bit without damaging anything in the motor?

Thanks,

Dan


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## Too Many Projects (Nov 15, 2008)

Sounds like it may have a high pressure oil pump. I would go to a 10-40 oil with the zinc added or use the ZDDP, like you mentioned. Synthetic oils are great but tend to weep/leak out of older engines that don't have the tight tolerances of modern ones.


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## 21553 (Sep 30, 2012)

Too Many Projects,

Thanks! I have read a great deal and found that 10-40W is recommended for the Performer heads. What brand do you use? I will stay away from synthetic. 

Dan


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## BearGFR (Aug 25, 2008)

I'm running Rotella T 15-40 in my car.

Bear


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## geeteeohguy (Feb 2, 2008)

I too have been running the Rotella diesel spec 15-40 or the Delo diesel spec 15/40 for a long time with no issues. Added ZDDP is a plus, too. The factory fill for these engines is 10/30, which I've also run with an additive. 20/50 is too thick for an engine that has factory spec tolerances, IMO. OK for a loose engine, but not for most applications.


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## Too Many Projects (Nov 15, 2008)

There are aftermarket oils with the minerals added to protect flat tappet cams but I use Mobil 5000 with ZDDP. It is hard to find it in 10-40 anymore and have been forced to use 10-30 in a couple of my cars now. No issues with lubrication.

If you decide to use 15-40, diesel oil doesn't protect the cam as all the minerals have been removed from that to, so the use of ZDDP or equivalent is still necessary. I run Delo Super 1300 in my Pete.

20-50 is for air-cooled engines like my Harley...

Eastwood sells ZDDP for about $8 a bottle and occasionally $6 on sale. I stocked up some years ago and still have 6 bottles left.


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## geeteeohguy (Feb 2, 2008)

Rotella and Delo still have ZDDP, more than conventional oils by a bunch, but I agree, it's not nearly what it used to be, say 2 years ago. An additional ZDDP additive is a good plan. That said, the diesel spec oils are tough, and do an excellent job. When I inspected the rod and main bearings, cam, and cylinders on my '67 400 2 years ago when I had the engine out for a rear main seal, the parts looked brand new. With 23 years of service and 77,000 miles on them. Good stuff.


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## propuckstopper (Jan 20, 2012)

*Oil*



66GTOMN said:


> Hello,
> 
> I have a 1966 GTO with a 1976 455 with Edelbrock Performer Heads. I am curious what oil you guys use?
> 
> ...


In my recently-rebuilt 1965 and 1968 GTO engines (both completely stock), I am using Amsoil Z-Rod 10W-30. It is supposedly formulated with elevated ZDDP and contains additional anti-rust additives for storage.

I am certainly not an Amsoil disciple, but I have used their products in high RPM snowmobiles and motorcycles with great success.

As an aside, the 1968 GTO engine was broken in with Rotella 10W-30. The 1965 engine was broken in with Amsoil 30 weight break in oil.

I have heard good things as well about Joe Gibbs Driven oil. They offer products that suit our needs as well.


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## 21553 (Sep 30, 2012)

Thanks to all that have replied. I have ordered in some Lucas Hot Rod oil 10-40W. It seemed to have the highest levels of ZDDP.


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