Hi there - with a little more info I can give you some numbers which may be of use?
Firstly, the bad news. I can *PROMISE* you that no-one weighing 103kg's will run a 10km in 35 minutes. Your body is capable of consuming oxygen at a particular rate, described at the VO2max, or the amount of Oxygen your body can consume, in ml, per minute, PER KILO. So by multiplying your VO2max by your weight in kilo's we can work out your engine power, ie the total engine power of your cardio-vascular system if you like. Once this is established, there are other genetic parameters to take into account, and lactate threshold which varies from person to person, the mechanics of your body, but hell we have to start somewhere...
Let's take some greats to start with. Seb Coe had a VO2max of 82 and weighed 54.5 kg's.. which means his engine ran at 4469. Lance Armstrong runs an engine around 6600 or so, he is a genetic freak with large heart, lungs, all abnormal and off the scale, so we are NOT there...
Since you are looking at a weight of 103kg's we can take a decent engine power potential, 3500-4000 and divide that by your weight giving a predicted VO2max of 35-40 ml/min/kg. This VO2max will correspond withing 5% or so with a time, ie at that VO2max, you can move your weight through a distance, at a speed, or at least our AVERAGE person can. This would put you at 103kg's in the 50-56minute range.
Firstly, 50-56minutes is a great time to run the 10k in. forget professional atheletes, forget records. 50-56 minutes is a good time.
Think of this - take your typical 55kg 10k runner and give tem ANOTHER 55kg's to carry, let's see them do a 27minute time then!!
It a balance of weight, and engine power, and a smattering of personal genetics, lactate threshold, skeletal mechanics and muscle group focus, and running economy.
Give us your target weight and height and I'll narrow it down a bit for you. Personally, at 103kg's I'd get on a balanced diet and get down a bit before putting pressure on yourself, and more to the point, your joints!