2014 501 Husaberg rear Spring upgrade

Hi there guys,
I am looking at heavier springs in the front and rear of the bike.

I have just noticed I have a rear straight rate spring from a 2004 berg sitting here which is a WP 81-99/260. This 2004 berg spring is 10mm longer than the KTMs or the new berg 2014 spring.

There appears plenty of thread on the PDS unit to accommodate this 10 mm longer spring and I don't think it will interfere with bottoming.
I am just thinking because KTM have made so many changes over the years changing mounting position , pivot points and so forth of the PDS. Have KTM changed the spring types and rating from model to model , or do they keep using the same type of generic springs?
just gives n/nn ratings and not rider weights for springs in the parts list.

Was looking at sticking this old berg spring in the new berg and see if it works ok? It would be better than buying a new one if it works.
my riding weight 95-100kg.

Any response will be greatly appreciated , will save me experimenting.

Thanks for that John,
I remember now getting confused on the same thing a number of years ago.
So a WP spring with 81-99 indicates 81nm and 99nm is progressive.

The numbers WP 72-250 (2014 standard bike spring) indicates 72nm and should be a straight rate spring.
So as you say, any WP spring, that has the same corresponding numbers on the spring out of another bike model, so long as its suited for my weight should be fit for purpose.

Clearly the 81-99 as you say , would be way to heavy rating and may not be suited to the straight rate spring valving in the PDS unit on the new bike.

I will look for a WP 76 or next up rating from there.
Thanks,
John.

My next thought is go progressive or straight rate in these bikes,
has anyone got a preference and why?
I spoke to a guy the other day who used to be all go with the progressive rate springs, but has since done a full circle and prefers the straight rate now.
I would think WP would have done a lot of testing on the recent PDS set ups and there is a reason they run with straight rate , they must work better overall. The guy I spoke with also said when going heavier springs and if you are borderline into a heavier rating with rider weight, he preferred to go with a slightly under rated spring.
Anyone got a preference or experience with either.
Any input would be great.