Front spring rate with Camaro clip & 1959 fleetside

[dunce79]

Getting ready to buy a QA1 coil over shock package for my 59 apache shortbox project. Has a 73 camaro front sub and will have an LS1 with automatic trans. What do you guys recommend for a spring rate up front. Stock camaro spring rate seems to be 300lb in. Not sure but I don't actually think the truck will end up weighing all that much more than a camaro when done. So I'd just want to firm up the ride a bit and add a big sway bar. Would you go with 350lb in springs or 450lb in springs. Kinda leaning towards 450. Here's the package I'm looking at. Just for street driving.

http://www.summitracing.com/parts/ha...450c/overview/