72-74 heater box oval manifold flange differences?

[hometurbine]

Hello all,
I'm swapping 72-74 heater boxes on my 2L engine since the ones on there were internally damaged (broken aluminum casting and PO welded the boxes shut). Original one on left in image.

My replacement ones had a missing header flange so I cut one off of the original one to weld it on the new one, but then it didn't fit over the manifold. They are close, but not exactly the same and I would really have to thin the wall down to make it fit.

The original ones have a stamp of "49692", are smooth all the way along and the stud bosses have recesses in the outer wall. The other ones have a step in thickness along the length and widen at the bottom where they fit over the manifold and have a flat spot (I need 1 of these).

Can someone identify what the difference is and how to get another one? Or if someone has one that would be great.

Thanks
Bill

[old DKP driver]

I can't say i remember different pipe flange diameters for 72-74
Except, there were 2 different manufacturers
Heater box part numbers 72-74

021 256 092 AC right side

021 256 091 Ml left side

021 256 091 J left side (with egr pipe)
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V.W.owner since 1967

[Wildthings]

If you are going to arc weld it on the pipe does not need to fit into the recess. You will need a way to accurately align it though.

[old DKP driver]

Like Wildthings mentioned
if you have an old cylinder head or have access to one then bolt the heater box to one and then tack it in place.
_________________
V.W.owner since 1967

[hometurbine]

Thanks guys for the suggestions. Yes, I can make this work by cutting to fit and welding. I was hoping for a more elegant solution, but I can make it work. So no one else has had this issue? Maybe it's just me....

Due to budget I'll make this work for now, but as far as new ones go are people generally pleased with the Dansk 72-74 ones?

Thanks
Bill

[WhirledTraveller]

I know the later '75-78 style F pipes where made of special non-corroding high nickel alloy. Not sure about the earlier style. Something to consider when planning to weld.
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1977 Westy, Automatic. Big Valve heads, CS Cam.