My engine guy will be assembling my 470 stroker soon as the machine work is just about complete and I could use some recommendations regarding a couple of things. First, I need some advice on cam selection/size. My intent is go with a solid lifter, flat tappet cam this time. From some of the information I have read regarding other similar builds, it looks like a cam anywhere from 560 to 620 lift is typical. That being said, I would like to have a fairly lumpy sounding cam if I can as I have never had much more than a stock grind cam before in any of the cars I have owned. The car (69 Dart) will be primarily street driven with as mentioned, a pump gas 400/470 stroker, Edelbrock RPM heads, 10.8 comp. ratio, 870 Holley carb on an Edelbrock RPM intake, 727 trans. with 3200-3500 converter, 3:73 gears and 29" tall tires. Second, my engine guy is telling me that because I want to go with a solid flat tappet cam that I need to get different valve springs as the springs that came on the RPM heads are more suitable for use with a hydraulic lifter cam. If this is true, I could use a recommendation on replacement valve springs as well. Thanks in advance.