Hmmm my buddy was telling me to change the valve springs when he dynoed my engine. I got an old 302 with flat tappet cam (CC: .500/.500 lift, 224/224 durr, 31-414-3 cam) stock E7 heads from a truck, airgap intake, 650cfm dp carb, stock bore KB pistons 9.6:1 CR. Anyway I left the stock valve springs in. And after seeing the post with the pics of the slapped piston, I'm kind of worried. So I think I'm going to order some 972 Comp cam springs with 328lb spring rate (what comp cams recommends for this flat tappet cam). This should be enough, what happens if you have too much spring rate? BTW I got 278HP and 335lb-ft of torque with this engine. I got a 351W begging for a rebuild but I'm getting some experience with the 302 first.

 

On a flat tappet cam............besides robbing some H/P it'll eat the camshaft smooth as a baby's butt not to mention possibley bend a push rod or two if yer runnin stockers. No advantage to over buying.