wossner pistons

hallo
im going to put wossner pistons in my engine
is someone who using them has any problem that it is from the pistons.
what are you suggesting on put forsed conecting rods?
is it usefull or not.
im going to use the specco head casket but what size 1.6 1.9 1.4 ?
i have make a rebuilt on that engine 10000km ago the engine has no wear then .
after 10000km and a normal driving the number1 cylinder go down for a 0.3mm
is that possible.
and what can gause this.
spesially in one cyllinder
the piston is wased with oil
and the rings wasnt brake.
thangs