I rebuilt my 70 340 about 5 yrs ago, 0.30 over w/hyperutectic pistons, Mopar performance original profile cam i believe they call it the restoration cam, Eddie heads right out of the box for a 10.5 to 1 cr, Mopar performance electronic chrome box. Engine runs very strong with a ausome sounding exhaust note. I run pump 91 octane which is all we can get in Caly no pinging at all, one problem i had with the eddies was where the alternator sits in a pocket on the factory heads there is no pocket on the eddies, you will have to do some tweeking with the brackets & get different length belts. The purple shaft is the biggest cam i would want in a street driven car w/a/c & power brakes. Im running a stock Carter AVS. Hope this gives you some insight.