Exhaust double-down pipes

[hopsedge]

I have my intake and exhaust manifolds removed, in part to replace the gasket at the double-down pipes. When I bought this car a few yrs ago (‘67 SV) a pair of headers came included in the misc parts bin. I do not know whether they would fit, but my question is:
Should I bother trying? What changes might I expect & what problems could possibly occur during installation (or afterwards)?

Also, even to dry fit the headers I will need to remove the double-down pipes. This leads to two more questions. 1) after removing the clamps beneath the car, should the double-downs slide out (i.e, forward)? How easily should this occur? Do I need to tap lightly on a wood block to break the friction at the male/female union that was formerly clamped together?
2) Instead of the headers, how about a stainless double-down, such as sold by SS? Mine is very rusted, at least cosmetically.

 

[jumpinjan]

2) Instead of the headers, how about a stainless double-down, such as sold by SS?

Sure, they will work fine.
Jan

 

[Acollin]

The likelihood of those of those pipes coming apart “ easily” is slim to none if they have been up there together for time out of mind. Any signs of someone being up there before?
That said , it could happen.
My guess would be they would “dent” with light and more serious banging and not come apart and crumble ( my story) , if badly rusted, when shown the business end of a woodblock and hammer.
It might be time for some new pipes.
Good luck

 

[husky drvr]

What changes might I expect & what problems could possibly occur during installation

If the headers you are asking about are for an early series, IIRC, there will probably be interference between the #1 tube and the sV alternator.

As far as separating the exhaust parts, that will depend on how badly the intersections have been deformed by previous clamp tightening.

Hope this helps,

 

[hopsedge]

…Also, even to dry fit the headers I will need to remove the double-down pipes. This leads to two more questions. 1) after removing the clamps beneath the car, should the double-downs slide out (i.e, forward)? How easily should this occur? Do I need to tap lightly on a wood block to break the friction at the male/female union that was formerly clamped together?

Well, I can at least report back on the resolution to one of my questions. I reinstalled the pipe clamps onto the double-down but forward of the Y-union. I sprayed the union with PCBlaster and the started tapping on a wood block tested against the pipe clamps. Top, bottom, one pipe, the other, repeat. Worked like a charm. The male double-down slid right out of the female Y-union little by little until it was free.