I know there were some earlier postings on this, but I cannot find them in the archives (or the question I want answered isn't there) so being a one toolbox mechanic......I cast myself upon the graces of this helpful group and I hope I can describe this sensibly.

I currently have a single downpipe exhaust manifold on my B-18 and would like to replace it with a later double downpipe version. I have a double downpipe manifold but it appears that the portion of metal that bolts the manifold to the head (the face) is thicker on the double manifold than the original single version.

Now there are two locations where the bolt holds both the inlet and exhaust manifold (where the throttle springs attach). These will now only tighten down to hold the new double manifold in place (because the face is thicker). There will be about a 3 mm gap between the bolt and the inlet manifold - so the inlet manifold will not be tight against the head in these two locations.

I looked at three options:

1. shave the double exhaust manifold along the face by about 3 mm to match the face thickness of the inlet manifold
2. use "half-washers" (about 3 mm thick) for the inlet manifold so the bolts snug up both the inlet and new manifold
3. use gasket material to create a thicker gasket (>3mm) for only the inlet manifold face as a way to build up the face to match the thickness of the face of the new exhaust manifold.

Although option 1 would be the cleanest, door #2 or 3 seem most appealing but may have some downsides (like leaking for #3).

Any thoughts - or have a missed something.

thanks.

waggin

1965 220 wagon
1985 245 turbo wagon