1. Either cam will work fine as a daily driver.
2. A set of .650" springs is exactly what I'd use. Specifically, I'd go with a set of PAC 1221 springs. --->> http://www.racingsprings.com/LS-Engi...-1221/Item/766
3. A good 3000 stall converter.....I like Yank, Circle-D and Vigilante.
4. 475HP to the wheels is a bit of a stretch. I would think you'd see something around 430-450 and maybe 16 mpg.....depending on the nature and amount of your city driving.
5. Long-tube headers and at least a 2 1/2" duel exhaust are a must!
What conversion kit are you gonna use for the install? I went with Muscle Rods. --->> http://www.brphotrods.com/products/7...cts/index.html
You'll probably need a costume made (for length) driveshaft......so be prepared for that possibility.
Best of luck!!