Check out 440 sorce.com they have good stroker kits at resonable prices and ive heard nothing but good about there stuff.They have 400/451 400/470 400/500 and 400/512 kits i believe.there kits are all around $1300 or so.
exactly, its about $1500 if you want the rotating assembly ballanced. bolt on a set of ported cast iron heads do a little ignition and oiling upgrade and seeing 550hp is not out of line. I talked to the guys at the 440 source back when i wanted to put a big block in my duster, they know what they're doing, great prices.