I have a 1950 1/2 ton pickup with the Patrick saginaw 4 speed and 3.55 rearend conversion. Drive it about 60 miles a day doing about 60to65 mph. I think the engine was rebuilt with insert bearings by local Norwegian rancher. Would splitting the exhaust manifold, Fenton headers, or Clifford headers be a reasonable improvement? I would like to have good cold weather performance.