First step in the conversion is to modify the tubes on the top of the sender for the -6 AN adapter fittings. The small bulge on the end of the 3/8" line and the 5/16" line need to be removed.
Cut them off as close to the bulge as possible, but the OD of the line must not be enlarged or the fitting's ferrule will not fit correctly. Deburr both the inside and outside of the lines once they are cut off.
Here is the Jeg's Fitting (for the 3/8" line) taken apart.
Slide the red part of the fitting over the end of the 3/8" line followed by the brass ferrule. Screw the blue part of the fitting into the red part and tighten per mfg's directions to crushe the ferrule and make the seal on the tube.
Here is the assembled fitting on the sender:
Now, repeat for the 5/16" line. The Earl's fitting is a little different shape on the tube end, I needed to bend the support tab on the top of the sender down off the tube before putting on the fitting. Once the fitting was on and tight, I bent the support back up and around the tube.
Here is the completed fittings on the top of the sender:
Leave the center tube (1/4" diameter) alone. Use a regular hose and hose clamp to route a vent tube up and out of the way on this tube of the sender.