I used a brass 5/8

 

any problems with the brass on steel threads?

 

ill sell ya my kit for $20

 

i dont need a whole kit, i just need a cap and im not looking to spend more than a few bucks

Well, I got brass because it was softer than steel. The thread pattern was not the exact same, so when it screwed on, it basically reformed the threads. Do you have an old manifold that is NOT on the car? You could take it to a hardware place. I made a post a few months back and it has the part number for Home Depot.

29296 5/8" flare cap it was 3.30

ill be hitting up lowes. we dont have a home depot close here. yea i havent put the header on the car because i wanted to put the cap on first. i might just take the header with me and check it out in the store. i think the threads on the header are metric which could be why yours was off...not to mention that it's brass.
do you have any leaks on it? it's not coming off again so if it seals i might just have to crank down on it.

 

No leaks. No problem. I threaded it all the way down, then took it off and you could tell it re threaded it. If I have any problems with it though, it will get a SS one and call it good.

 

my lowes didnt have the 5/8 nut...i did find out that ford makes a delete plate and nut for it though...i have the part number but cant find the nut anywhere online...

ford part number for the cap:
W705609-S430

 

Did you take the manifold? You can just try different ones. That's what I did.

 

You can take the the system off the car, leave a little of the pipe on the original cap, fold the end of the metal pipe, and then fill it with some weld. I got an exhaust shop to pool some weld in for free.

 

Can you weld?

 

my brother can. i would rather have a cap though. doesnt cause as much attention that it's deleted compared to a pinched pipe. i was looking at it today though and with the way that thing is, it looks like it's actually an AN fitting...either a -10 or -12

 

IDK what it is. Before I did that, I had taken the nut to Home Depot to try to find a cap, but they didn't have any caps that were the same size and thread... I ended up going with the backup plan.

 

I have a better way that doesn't involve having a piece sticking up. Take some JB weld and and 'glue' a metal slug on the inside on the cap. It will seal it up and make it a cap, rather then a nut. Maybe you can hit it with some engine paint and call it good.

 

i dont think jb weld will hold up to the heat conditions of a header. thats just asking for it to melt and create a leak.

 

That's a good idea, for WLJohnson. Mine is already on the car, that thing was a royal pain to get off. All the A/C stuff was in the way so i had to take that header off to get it off the header, but I had to disconnect the mid-pipe from both manifolds because the exhaust system is sooo tight. It's hard to see it unless you are looking for it, so I'm happy.

 

Get your bro to weld a slug in there.