Ok so I just changed my head gasket on my 83 D150. It was running at temp and all that good stuff before I changed the gasket.Now it'll be okay if your going under 40- 50mph but when i put it in 4th for hiway speeds it crawls up to 210 and slowly gets higher, i have a 180t-stat in it now. In the mornings it doesn't have this issue, is it possible i accidentally flipped the gasket and covered a water jaket or something? Not sure what to do so if anyone has any idea please let me know.
