spring rate

[werty]

So trying to come up with a better spring rate for what I ride.
I am running 06 trx450 shocks on the front of my cannibal. Springs are way to stiff. What's the stock rate on the ohlins?
I'm about 170 to 180lb and ride ruff desert and creek beds. The last jump I did was off a waterfall 7-8 feet down. I'm also thinking of going +2+1. How with this affect the spring rate needed?
any help?

Thanks in advance.