I had a real tough time finding headers to fit my 51 with a 350 and mustang 2 front end. the steering shaft is in the way. got a set of headers from speedway. the steering shaft passes through the headers on the drivers side and both dump ou the rear. they fit real well.
Speedway part number 930C5 55-57 chevy headers. I have a set of polished block huggers ( brand new) from my trial and error- may let them go if you are inrested PM me.
I am pretty sure they came from speedway.or summit.
I will go through my files and see if I can find the paperwork.
I can send you some picks
Maybe around 150 I think they were 275 new