Slant 6 Exhaust Manifold Washers

Troub, check this from a far more knowledgeable guy than me...Dr. Dodge:
" The two acorn nuts go on the two top, outer end studs, with the coned shaped part of the nut fitting into the dished/conical part of the round brass washers. The center three studs (2 top and 1 bottom) get cup-shaped round cast iron washers, cupped faces towards the head. Everything else gets triangular butterfly washers. (Link to more manifold installation instructions)

Note that "later" SL6 engines came with only one round conical washer in the top center position, all the other were triangular type. This combination is also acceptable.." Read cheaper but a little tough to get going on the bottom rows.

instructions