are 14-150lb springs good?
 

found some 14-150lb springs for my coil overs. wondering if there good for 1/4mile?

They are a drag spring, however a 150 spring is pretty loose for a 4.6, you may run into coil bind. I personally run 14 175's and I only have a v6 under the hood..

Those are more a drag spring so yes they would be fine if you're setting up your car for the 1/4 mile. Sometime it takes trial and error to figure out the right spring rate.

I'd run at least a 14-175 spring. I mean for a 4.6 N/A i'd run a 14-150, but with the addition of all your turbo stuff, I'd run the heavier spring rate.