If they are the same as Series II & III (I replaced my fronts years ago and can't remember) then why not buy from the UK.
Shock absorber-SWB std front - Paddock Spares
Shock absorber-SWB std rear - Paddock Spares
$100 plus freight from the UK.
A lot of brands on Ebay I've never heard of, here are Armstrong rears for $50 each (probably the same as the UK price when you factor in freight).
New Land Rover Rear Shock Absorber SWB Series 1/2/3 RTC4232 | eBay
Here's some noname fronts.
New Land Rover Front Shock Absorber Series 1 2 3 SWB RTC4230 | eBay
Colin
'56 Series 1 with homemade welder
'65 Series IIa Dormobile
'70 SIIa GS
'76 SIII 88" (Isuzu C240)
'81 SIII FFR
'95 Defender Tanami
Motorcycles :-
Vincent Rapide, Panther M100, Norton BIG4, Electra & Navigator, Matchless G80C, Suzuki SV650
Bookmarks