Can one top off GC w/ M1 0w-40?

[WeyounDS9]

I currently have a fill w/ GC at 1100 miles or so.
No discernable drop in level yet, but since this boards is beginning to talk me into a longer interval I wonder...

At 3000 miles oil changes I never need to top off , but what if I go 6000 miles?

I am sure I will, and I have 2/3rds of a qt M1 0w-40 here.
Since my sump takes exactly 6.00 quarts I dont want to break open my special ordered cases of GC.

What do you guys think, should I used the left over M1 0w-40 as top off?

Fred..

 

[buster]

You can, but I'd use the GC. M1 is compatible with dino or any other synthetic oil.

 

[Al]

It will be fine. But what's the problem breaking open the new case. You'll probably need to add oil at one time or another.