Hey guys, I've got a stock '75 350 4-bolt in my 66 with a 4-speed manual trans. This car is a daily driver and I just want more power to have fun with...I'm putting on an Edelbrock Performer and a 600cfm holley, it already has headers. My cam choice was a comp extreme energy cam: 268/280 dur, 477/.480 lift. Somehow I ended up with the next larger size: 274/286 dur, .487/.490 lift. Should I send it back or will the other one be better for my application? Also, is it worth spending $750 for a set of world S/R Torquer heads: do they really make that much of a difference in power?? Thanks for any answers... Chris