PlayGround

Service Manuals:
There are no instructions or mention of how to attach these mounts in the FSMs other than basic statements to the effect of “install the bolts”.
Why does it matter if the washers are on top or below the straddle mount?
According to Dr Dick, the washers being on top under the bolt head is responsible (at least in part) for cracked heads at the threaded mounting holes for this mount.

Looking at illustrations in the FSMs:
In the 1964 FSM, there a 2 illustrations in the book showing the left side of the bike and a very good detail of straddle mounted.
On page 1B-7 picture (1B-2), in the front of the book, shows the washers on the bottom of the mount.
On page 3A-17 picture (3A-8), in the engine section, shows the washers on top of the mount under the bolt head.

The 1967, 1969, 1976 and 1978 FSMs all show the washers between the head and the straddle.
These old books were printed using dot printers and scanning a picture to get a better view is not that easy as the dots in the ink get bigger as well.
But the washer doesn't show up on top in these books.

So even if one were to try and research from the manuals, it's still a crap shoot from there deciphering washer orientation depending on what manual you have.

Parts Catalogs:
The parts catalogs, in general, show exploded views of how the parts go together (which is generally a good visual for installation).
However, below are some confusing aspects found in the parts books.

• 1957-1978 parts books all show the washer under the bolt head (on top of the straddle mount).
• 1979-1985 parts books all show the washer under the straddle mount between the heads.
  Starting in 1979, the head straddle (head strap) is no longer tied back to the frame. It just supports between the heads.
• 1957 parts book doesn't show the cross brace to frame bolt nor does it list the part number for it (shows up in the -58 supplement).
  It also shows all three cross brace to frame washers below the straddle mount (or side by side depending on perspective)
  The cross brace is missing as is the cross brace to straddle bolt and washer.
  All of these parts show up in the 1959 parts book however.
• 1957-1978 parts books (except for 1959) all show the original cross brace illustration with though the end was lengthened and holed for the horn bracket.

Due to the possibility of cracking the head at the tapped holes for the straddle mount;
Click Here to reference Factory Top Mount Installation per Dr Dick on the main Ironhead motor mount page of the Sportsterpedia.

Washers on top of the straddle mount (71 XLCH). (as shown in the parts books and most FSMs) 1)	Machined area on head for the straddle mount. (notice the binding that occurred in the left pic) 2)