thanks guys. at the present time i'm running 900 fronts and 325 rears. heavy bars front and back . the reason for asking is because i feel i have some under steer issues.
Are you still using the stock rear suspension parts? The best thing for Mustangs is to upgrade to the Steeda 5-Link or equivalent. To the letter of the rule, you must leave the upper arms in place. Bushing material is open, so some soft foam will render them useless. The traction bars take their place and all is in harmony
From there I would reccomend using lower spring rate up front and see what happens. If your ride height is too low you end up with the front roll center too low which makes things worse.