i have a 71 mustang fastback with a 400 engine w/c6 auto in it. A friend of mine is selling his hedman 88220 headers http://www.jegs.com/i/Hedman/500/882...-1#moreDetails and i was curious if they are compatible.

 

bump still wondering

 

Buy some header gaskets for your engine. If they match the headers then they should work.

 

Have you tried calling Hedman and asking them? The deck height on the 400 block was much taller than the Cleveland so I kinda doubt those headers will drop in and work even if the bolt holes and primary tube match up. I think it is going to be hard to find "out of the box" headers that will fit a 400 in a 71 Mustang perfectly since the Mustang never had a 400 put in it from the factory. A good performance shop can built you a set though.

 

I was wondering about the deck height on the 400 that is why I didn't answer

 

yeah one of my old trucks had a 351M and it has the same deck height as a 400 and i didn't find that out until i tried to bolt my hustler race headers to it....needless to say, after i threw them across the shop, they won't fit....