That's pretty stiff... good thing you have another car to drive daily now.

I'm just trying to find a rate that matches the goddamn over stiff shocks in my coilovers... the 390lb/in springs in there are too soft, and the car hops on the valving over little bumps and undulations.

Plus, w/ the 6MT going in, my car's gonna be heavier, and since I got a daily driver I can deal w/ the stiff springs.

That's right, I forgot about your shock problems. You might want to try a smaller step (or two) up; we've been doing a lot of ride testing in the Mustangs lately and even a 25lb/in rate increase can make a noticeable difference in ride quality. If you have scale weights for the car I can run it through my ride frequency spreadsheet and compare it to our stuff, let me know...

Awesome. I've been planning on corner balancing the car soon w/ the SCCA scales. But I have to *have* my car to do that! One of these days I'll get it back from SS... stupid driveshaft!

I'll certainly have some suspension setup work to do w/ the new weight of the larger tranny in there... perhaps 550 is too high... but I'll never know w/o some data and probably a few attempts w/ different spring rates. Luckily, I can use generic 2.5" ID springs, so I'll prolly just get a set or two of Eibach springs and see what works.

Yeah, with no other info available I'd start going up in 50lb increments. Shoot me the scale info though and maybe I can get you a better starting guesstimate.

Will do. I'll steal the SCCA scales as soon as I've got the car back from the shop w/ the new tranny, and get my cornerbalancing on... then I'll have some data for you!