440 head question????

I have a stock 1968 440 that had the stock 906 heads that are wasted. I can get a good deal on a set of 1974 902 heads. I've read that the 902 heads have a flatter intake port(?) and added cooling passages. My question is are these 902 heads any good or should I look for a rebuildable set of 906 heads? Any info would be great,Thanks.