'Query'! don't you just love the English..?!
...Hey Sam (from another one!), you don't sound 'crazy' to me!
Most guys can expect a 6 inch (+/-) penis when it's all over, regardless of 'genetics', or dad or anything. He (and you) are, afterall, a part of the larger species, so these things are more determined by larger humanity we all belong to, rather than individual factors. Unless, of course, your dad is a midget!