AE pistons fit Losi shocks and vice versa. I don't think AE springs fit Losi dampers as the Losi dampers are a smidge larger outside diameter.
Losi Piston to AE equivalent
#55 = .052"----- #1 = .052"
#56 = .0465"---- #2 = .0465"
#57 = .043"----- #3 = .043"
Losi to AE Spring comparison
http://www.xfactoryrc.com/rc/Tech/SpringConversion.php
Hope this helps
(oOple search & Google are great
)