If you are bored, I have a challenge (for everybody).
1977 was a very odd year for the f250 4x4.
77 was the first year the 351M and 400 engine was used in that truck. And early production for that model year still used the "highboy" frame, divorced t-case and the tall stance that everybody loves.
Here's the challenge:
Find headers that fit the 77 4x4 f250 with 351m or 400 engine that are not fender well exit headers.
