front coil over confusion
 

Okay the recommended spring rate for front coil overs on our cars are 75 to 100, then why does it state in the service manual 1 red paint mark 500-514lb, 2 red paint marks 516-529lb, 3 red paint marks 531-545lb for the stock springs?
Also what would be the proper length for the coil over springs 10 or 12 inches? (2.5inch diameter linear springs)
Can someone please clarify this for me. Thanks
Alex