440 differences??

What exactly are the differences in the 440 motors that came in different cars? More to the point what are the differences in the bottom end? I have an oppurtunity to purchase a complete 440 from pan to carb w/ 727 tranny for $900. It is a 1972 w/ what I am told very low mileage, but it came out of a RV... Now if the bottom end is just as good then it shouldn't be a big deal because I am building the entire top end, Cam, Heads, intake, carb, etc. What kind of performance issues would I see? This will be going into a 73 Duster and not a daily driver (I have already looked into doing the swap). As always your advice and opinions are welcome and thank you all for your time concerning my project. I will start posting some pics as soon as we get rolling on some real progress. Right now we're just cleaning her up.