Ser III fuel sender for 88" will the 109 model work?

[TJR]

I have a '73 Ser 3 88" NAS with an original and old but working fuel sending unit... . I've purchased a new tank from RN and would like to use a new fuel sender. the PN my parts guide says I need is LR PN 555844

However... I have in my pile of misc parts an unsed non-genuine sender unit numbered 90560612 but the arm is much longer and is two piece as shown in the link below.. Older RN catalogs indicate this to be for a 109 diesel or petrol??

When I've search on line it seems this PN may have superceded the orignal number with this number as well ? If alter the arm will it work just the same? has anyone else run across this?

http://www.landroverorphanage.com/shop/article_555844/555844-Sender-Petrol-Front-Fill.html?sessid=S4ze6YeJeoQ6Bw4LgLDXiQnzicPSjdnmpCKeT0T3wSMx5nEmWjzaVkzTnW2Ifw6u&shop_param=cid%3D344%26aid%3D555844%26

Thanks... TJR