I am building another engine for the new Chevelle addition. It is currently a 350 with stock pistons, 601 heads, no idea which cam and headers. I have heard pro's and con's about the 305 601heads. One of the cons I am currently experiencing is detonation even with 93 octane fuel and just 6 degrees of timing. I built my 71 with Vortec heads, Edel. performer intake, CC XE262 cam, headers and a posi with 3.31's and am somewhat satisfied. I am looking for lots of low end torque from the new combo and be quicker than the 71. Now do I keep and build off the 601's? Is it worth the expense and effort? OR do I go with Vortecs again try the CC XE268 with stock pistons? Will the compression be an issue with cam/ head combo?