Chevy 357cu. in. W/Comp Cams XE268H Everything runs great but I'd like to move the power band or when it comes on cam just a bit lower in the rpm's. Right now I have Comp Cams black bushing on the timing sprocket, this put the Cam straight up. If I use the 4° bushing (advancing) will this bring the power band down a couple of hundred rpm's? Right now it comes on cam starting at 3500 rpms. I've never used timing bushings before. I know I will loose some top end power buts that's OK for now. I've read that changing to a 2° didn't do much, thought I'd try a 4° first or should I go more than 4°?