what year frames are interchangeable for a 66 coupe. both front corners in front of cross member where it turns and goes inside the wheel wells are rotted. it has been patched on outside of frame but insides are rotted. is this common? would it be better to replace the frame?

buzz,

I can't tell you what will work, but I know that topic has been covered here several times. Try searching in the Body section. I bet you will find it.

Good Luck.