the canfield s are good heads for the money .but it sounds like to me you are looking for somthing mild and not to wild all the stuff that i talk to you as been used on the steet . the aluminum heads can take one point more cr than iron aluminum is not efficient like iron . aluminum is look cool but a good set of iron heads will make more hp so put a set of Oval on it and use a smaller cam . but i have been down this road with customers when you spend big$$ and some guy whips you with a set of gm iron heads on a stock 454 type engine will you be ok with it i am not trying to come off as smart a$$ but i have seen it so build it with a set of iron heads and take the money put it in a custom roller cam with a4-7 swap this is good for 20 hp call howards and take to john. i have race a lot of guys that had lot of$$ and beat them . the guy with the stock type big block it was me