I have a bad lifter in my 73's 350 motor so im going to put a cam kit in it while im at it, but I dont know much about which to buy. Ive been looking at the ones in LMC and I dont know what all these numbers mean. Such as "Degree Duration", and "Gross valve lift int/exh". I can guess what they mean pretty much but I dont know if I want higher numbers of what or lower. I dont want a really big cam, nothing that will hurt gas mileage much at all, but I want a mild one. Also it says what the cruise rpm's are for each, what does that mean? Finally, what are the numbers for these things for the stock cam to compare these to?