Thread/Bolt Size for H-Pipe to Header (Stock)

[caine0]

Thread/Bolt Size for H-Pipe to Header Connection (Stock)

I have to pass aircare by January 9th, so it's time to snap on some stock headers and a stock h-pipe. I need to know what I have to buy to connect the h-pipe to the bottom of the headers please. It's just 4 large bolts with nuts on the other side of the connection is it not? What size are they? Thanks.

Also, is there a part # I should know for the gaskets I'll need for the headers?

Incase you're wondering why I need to buy the bolts, I don't have any on there right now because it's a welded exhaust.

 

[jrichker]

3/8-16 US standard coarse thread. The stock nuts have a reduced hex head on them to fake you out. Home Depot will probably have some nice stainless steel nuts for about 75 cents each.

Use lots of antisieze compound on the studs & nuts when you re-assemble things. It will make them easier to remove next time, And yes, there will be a next time...

 

[caine0]

This is a Canadian mustang, does that make a difference on the size of them?

 

[jrichker]

No. The cost of manufacturing and stocking a different size stud & nut for Canadian cars would be too expensive. In this case, one size does fit all...

 

[caine0]

Thanks jrichker, how about the header gasket #?

 

[caine0]

Alright I got the header gaskets today, the part # was Fel-Pro 1415.

All I need to know now is the bolt/thread size for the h-pipe to backpipe connection. Anyone know? They're a bit smaller than the header to h-pipe connection are they not? Thanks.

 

[jrichker]

Same size - I swapped one of the reduced hex nuxs off of the H pipe to muffler last time I had the H pipe off. It was easier to wrench the header to H pipe when they all had the same size nuts.