Thanks for all the replies

1956 F100 272 4 speed
Northern California

I was thinking of mixing 50/50 VR1 10w30 and 20w50 and getting something like a 15w40.  I THOUGHT I read recently somewhere that they said that VR1 was good for AT LEAST 3000 or 1 year.  

Maybe I'll just order more of that Amsoil Zrod for next year.  Been running 10W30 the past couple of years but thinking maybe 10w40 is the way to go.  Oil pressure is always good- 50 at startup and 40 plus at hot idle.  

I still can't find VR1 10w-40. 10w-30, straight 40, and 20w-50, but no 10w-40. 

I did a search for vr1 not fgor use in street cars and found this.

We are not able to join the forums, but we can give you the answer you need, or maybe would like to add to the forum. Our VR1 Racing Oil is NOT just an "ordinary new car street oil" as listed. Our Valvoline VR1 Racing Oils can be used in street applications, but still contains the high amount of ZDDP (Zinc and Phosphorus). This information can be found on our Valvoline.com website, under the section where it lists the Racing Oils. We have also added the product information sheet for both the VR1 and the "Not Street Legal" Racing oils. As you will see, Valvoline still contains 1200 ppm Zinc content in our regular conventional VR1. It does carry the API Service "SM" rating, but this oil was not made to change for emission standards due to it not being a "ordinary street car oil." This information clearly states the amount of both the Zinc and Phosphorus levels in the oils. The main difference between the the "Not Street Legal" racing oil, or commonly known as Conventional and Synthetic Racing oils, and the VR1 is the Calcium content. Calcium levels are higher in the NSL oils, compared to the VR1, and the NSL oil is only recommended for 500 mile oil changes, while the VR1 is a 3 month/3,000 mile oil.
Valvoline stands behind the flat-tappet and more aggressive type cam applications 100% with our Valvoline VR1 and NSL Racing oils. The proof is in our product information sheets, which are online for the viewing as well.
Here are the product information sheets with test results for all of VR1, Not Street Legal conventional, and Not Street Legal Synthetic.
Thank you,
Valvoline
I prob wont put 3000 miles on the 272 in a year but I do change the oil yearly any got an opinion on the 3 month/3000 mile life

I would prefer 10w-40, but I've been unable to find VR-1 10w-40 conventional oil. Amazon seems to have the best price/w free shipping on VR-1 10w-30. I, too, have read that VR-1 isn't recommended for non-race applications. Does it lack detergents? Personally, I don't want to use oil that has to be changed more frequently than yearly/every 3,000 miles, whatever comes first, but VR-1 does have a higher concentration of phosphorus and zinc than Daily Protection 10w-40 conventional. 

I have been using Valvoline VR1 20/50 in a 1956 pickup 272 with lots of miles on it. I'm in California heat but also drive in winter. Should I be using 10/40 instead of 20/50?  Thoughts will be appreciated, Thanks 

1956 F100 272 4 speed
Northern California

Early morning thoughts on the subject.

The 10# per 1000 rpm for engine oil pressure is just a generalized rule that if followed, ensures no advanced bearing or journal wear.  Some engines get by with less than this depending upon the internal clearances.  Oil pressure is simply a result of restrictions to the oil flow so having no oil pressure present does not necessarily mean that there is no oil.  Just the opposite in fact as when oil flow is not inhibited, oil pressure will be low or not evident, but flow will be high.

With all that being said, oil pressure is important.  Oil must be at the bearings with enough pressure to generate a pressure wave between the bearing and the surface it rides on.  No pressure, no wave.  Bearing clearances and oil viscosity work in tandem with each other to create this pressure wave.  Too much clearance and no pressure wave.  Not enough viscosity in the oil and no pressure wave.  It’s a fine balance for that pressure wave or oil film to be created and still not be so thick or heavy that the oil will not flow from the bearing.  The oil flow must also be sufficient enough to carry the heat away from the rotating surface but not so inhibited that the bearing gets hot and prematurely fails.  Using an oil with too much viscosity with bearing clearances that are too tight for that particular viscosity will have a tendency to overheat the bearings due to the oil not flowing fast enough to carry the heat away.

Multi-weight oils were introduced in the early Fifties and helped to provide that balance in oil flow between cold starts and hot running.  While the cold starting with 10W-30 and 10W-40 oil are similar, the 10W-40 oil would be more desirable in hotter climates and provide an extra degree of pressure protection to the bearings.

When comparing oils from different companies, it’s important to realize that testing procedures and the ranges for the viscosity of their oils will not be standardized to each other.  Viscosity ranges in these instances will vary and not be the same across the board.  Company A with a 10W-40 oil may not be the same as Company B with the same advertised 10W-40 oil.  That’s the reason when I did a oil viscosity test on the dyno, I used the same brand of oil throughout the test as using other brands of oil gave some conflicting numbers.

Lorena, Texas (South of Waco)

Just curious:
With sole focus on traditional minimum pressure recommendation (10 lbs. per 1000rpm), could someone remind me of likely consequences if less? (10W-40 vs. 10W-30).
Too speedy evacuation of bearing spaces might promote metal contact? Or, might the benefits of increased circulation (cooling) outweigh risk of slightly bending the min. rule? How much of that rule is evidence based, vs. supposition/tradition?

6 VOLTS/POS. GRD. NW INDIANA

Sorry guys, I don't know why the link doesn't opoen correctly like it does  on my computer. 

64F100 57FAIRLANE500

                      If I did this right, the link should open the data sheets for conventional Valvoline motor oil showing zinc etc. content.   10W30 for the most part is what I used through the years in my Y-block and always had excellent oil pressure no mater the ambient temperature. I always add a 4oz. bottle of zinc supplement but that is probably not necessary.   If the link doesn't work, maybe someone can post it correctly.    Removed non-functional link.

64F100 57FAIRLANE500