Hi,
Regarding heart rate:
Your resting heart rate is fine, and does not put you in any danger zone. Your blood pressure is fine, but your diastolic (lower number) pressure is a little bit high, which is common if you smoke and have some kg's overveight.
Regarding heart size:
There are many causes (and types) of heart enlargement, what matters is if your heart is dilated, or if the walls are enlarged (thicker) or if the heart itself just is a bit overdimensioned. I doubt it's a dilation process if you are able to exercise that well. Anyway, a cardiologist should have a look at it with echocardiography (if it's not done already).
You mention what you should do, you really should quit smoking and eat healthier. You're 27 years old, and you should have some nice years in front of you, not worrying about heart diseases. This is important.
Hi Mike...sounds like you are one lucky man.....a normal heart rate is between 70 and 120 so you are great there and your blood pressure looks well within the standards as well. If you are walking uphill and not even getting winded and weigh 330 pounds that is totally amazing. I am sure that your doc told you that being overweight can definately cause an enlarged heart as well as smoking. I am sure i don';t need to tell you if would be best if you dropped off some of the weight.....as far as your vitals go and your readings....again you are super lucky to have such great ones...i would go on without worry but may want to try to limit my intake of calories to help yourself further....i definately would not be worried