Does anyone know where I can get after market headers for a 1988 E350 with a 460 (7.5L) in it? I have searched everywhere and can't find a source.

The closest I have come is 1A Auto but they only have headers without the smog tube holes. I need them with smog tube holes.

 

Thorley makes em

http://www.thorleyheaders.com/ford_headers.html

 

I recently installed a Gibson Free Flow exhaust system on my 1987 Motorhome which is built on an E350 RV cutaway chassis. It has a 460 CI engine. The kit included everything I needed and if I remember right - the headers were Thorley. Only ran into one fitment problem - I had to fabricate a new transmission shifter linkage arm because the factory OEM one was hitting the header on driver side when I tried to shift.

If you are not aware of it - the 460 engine on heavy duty use vehicles is notorious for snapping the original exhaust manifold bolts - if you do a search on the forums you should find more info.