I've used Fed Ex Ground, UPS, Greyhound bus and Fed Ex Freight for car parts including sending a driver side door for a 1965 Dart 270 two door hardtop in a windshield box that I got for free from a local body shop up
I ship it to a guy up in Canada by Greyhound to a small town in either MI or IL, CRS.
I used a bunch of small empty cardboard boxes I had to act as insulators in the box between the door and big box on both sides to keep it from moving around, that worked well up
Shop around to get the best rate and best shipping company scope up

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)