Well after last weekend I can surely tell you 550 lbs up front is too much ! We had 650lbs rear and they weren't enough. We will go 500 front / 700 rear respectively at a 7" length. We actually compressed the rears enough under full load to have fender rub. Make sure you don't over spring whatever shock you are running.

We had a friend in a Neon up the spring rates on his car and we just watched him bounce on down the front straight. Funny as hell. Glad I wasn't driving.