I'm wanting to get rid of the existing headers on my '78 with a 400 and replace with upright/drag headers through the hood. I'm wondering before I order the parts, is it a straight swap or will I run into issues with the new headers hitting other components? The ones I'm looking at have a forward offset which I hope will get away from my steering box. There is a non-offset option from DEC also. Any advice on this would be greatly appreciated.