Hi ppl :D
This is,according to me,the best build for AD Tank Hecarim.
Enjoy freely posting comments,don't forget to vote and,if u wanna,
use this build as much as u can.
Down below is a list of ''chapters'' u can read to see why
did I choose exactly this build.

This Build has been tested several times and has been proved very efficient in-game during every test.
Pros:
-Ionic Spark is the item perfect for farming and is also veri efficient in 2 vs 1 fights.
-The Bloodthirster will give you a lot of livesteal besides the second ability.
-Guardian Angel is very usefull because of the armor and magic resist it provides you with.It will provide you with a ''way out'' of situations like ganks,2vs1,3vs1 and more.

Cons:
-The boots are not necessary for hecarim as you gain a lot of movement speed from your third ability.U can use other boots that provide you with better stats(like ninja toby).
-The Thornmail is replacable with The Frozen Heart that provides you with 500 Mana and cooldown reduction(this replacement is not recommended because it is not very usefull during late game).

In my opinion,the runes should not be changed and here is why:
-The flat Armor Penetration runes are very usefull against tanks with a lot of armor.
-The flat Armor runes are usefull for boosting your armor in the very beginning of the game.That means you will take significatly less damage.
-The Magic Resist runes are usefull especially for fighting AP champs as it will reduce the magic damage you take.
-The Movement Speed Quintessences are my recommandation for every person as they give you not only movement speed,but damage too(check the passive).In combination with the build and the third ability they are guaranteed to give you 650+ MS.

Here are the main reasons why I picked these spells:
Flash:Most of the time your third spell will be on cooldown(during a chase and this is where flash comes in handy).You can use it to get a little closer to your opponent,using rampage or ignite(if your target is on low hp)and killing your target.
Ignite:If you really need to kill a low hp enemy,with no help from your teammates and you have to make it somewhere in time(gank,turret push etc.)this is the moment you use your ignite to burn your low hp target eventually killing it.Then it's just a short run for the thing you wanted to do.