97 bluebird 12 v mechanical 5.9 cummins

[Sunbear]

Just replaced the head and all gaskets drove from salem oregon to s.f. She has so much power now stays nice and cool . Used 2 qts of oil and 5 gallons of coolant no perceivable leaks when idling wheres.my coolant going?

[AlleyCat67]

Maybe the cooling system didn't get completely full, some air pockets or something, though you'd think that would have manifested itself with a higher run temperature or something.....

I'd say fill it back up, drive it for a while and see if it continues to drop..... after making sure you don't have coolant in your oil. That could get messy, and be expensive to fix.