I got the bright idea of installing headers on my 90 F150 302 4x4. Picked up a used set off ebay, sandblasted them and painted them with hi-temp paint. The manifolds unbolted with no probs at all, and the headers bolted right in without a snag.
Naturally, I knew it couldnt be that easy. Both flanges exit too low & just in front of the transmission crossmember, and at a slight angle to make it more fun. I took a piece of 2.5" pipe to the exhaust shop to have them tweak it to my 'exact specifications'...of course, it doesnt fit..no surprise there. So tonight I had to order some mandrel bent pipe to weld up and snake up and around the crossmember.
I have a Summit brand 3" muffler and a flowmaster merge pipe (dual 2.5" inlet to a single 3" outlet) which will fit right up in the event I ever get the piping that far back. I also ordered a tailpipe for a F350 diesel (I think its 3" diameter)
Until then, truck is enjoying an extended vacation in my garage.

 

sounds like the same problem a lot of people have. headers are great providing they can be used on a vehicle

 

Yes this sucks.. I don't know why they changed the header shape, the old set I had fit beautifully.

 

I ran into the same problem when I put the Flowtech headers on my truck. I ended up cutting back the collectors a little and used the flex exhaust from Autozone to run under the crossmember. Then I 'modified' the old y-pipe behind the crossmember and clamped it all together for now. Once I get my custom cage built and pull the body and bed off, I'm going to fabricate the exhaust better, but for right now it works.

You can see the pics of mine about halfway done this page I have:
Links and Pics

 

what brand headers were those? I got a set of flow-techs off of ebay for my 95 and there was plenty of room between the flanges and crossmember. this was an older set,i am not sure if they changed the design after that.

 

This was a new set. Conanski recommended them because his had plenty of room. But his turned out to be older too. Even he just got another set and was disappointed that they were longer than his old ones. I got these about 6 months ago.

 

I just left some "feedback" on the Holley website about these headers, we'll see if they respond.

 

Here is how I did the flowtechs on my 95 F350. Did em bout 2 years ago.

I Used 2 90*'s to get the pipe to snake around the trans pan and go over the crossmember vs under it.

 

Those still look like they dump alot farther away from the crossmember than mine do. I may look at something like that when I pull the bed off and can get at that much easier.

 

I donno, I just kept trying ways till I got it somewhat the way I wanted it. Ive had a change it a few times since then. I have to change it again now. I also have the E4OD and it seems like the crossmember is back farther then on my 88 Bronk with the AOD. But who knows.