See also in the Sportsterpedia;
….. *1957-1985 Oil Line Routing
….. *Pics and Information on stock IH Battery Trays and Parts

Click on any pic below to enlarge:

The 2 shiny ones below are 62-65 NOS tanks. Note that one has a notch in front mount bracket. A mistake?
The chrome one is also 62-65.
The 4-fitting tank is 58-61. It has the full rear weldment.
Note the bent supply fitting on the chrome tank. It's like this because of overtightening the drain plug.

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Aftermarket horseshoe tank (no drain): ^{11) 12)}

Here is a 1966 XLCH frame with a horseshoe tank installed. 65-69 XLCH frames have the boss under the right seat casting for a regulator mount.
The holes are drilled and tapped on 65 XLCH only but the boss stays thru 69 on XLCH frames.
The holes can be drilled and tapped for the 65 CH regulator bracket to mount there.
The 66 frame would be factory fitted with an angled bracket under the seat casting for a lunchbox oil tank.
With that bracket removed, the regulator can be mounted on the boss there.

66-69 XLCH frames have two tabs welded on the back side of the left seat post to mount the regulator.
These brackets, according to the pics below, DO NOT have to be removed in order to mount a horseshoe oil tank to the 66-69 CH frame.
You can see those two brackets in the second pic below on the left post with a horseshoe tank installed.
You'll need the horseshoe oil tank brackets to mount to the engine as well, front (62555-53) and rear (62552-52).

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