Question: My 6 yr old walking horse is almost 17 hands and about 1350 lbs.  A friend of mine bred him and sold him as a 2 yr old and I wanted to buy him then but his was like a great dane puppy, you know how their feet seem too big for their brain and they can trip over their own shadow. 
That is what he was like.  Anyway I found him about a year ago and bought him and he has matured quite a bit but still trips more than any of my other horses.  He has a huge overstride and can go all day but I am concerned about the tripping...will he ever grow out of it?  I try to keep him on the bit and ride with spurs to "remind him to stay alert"  He is shod with a size 4 light shod shoe in front and we try to keep the angle up around 52 or 53 and just a keg or not shod behind. 

Any sugestions would be appreciated

 It sounds like you are already doing the right thing.  It usually takes these 
"big guys" a little longer to completely mature and become more coordinated.  
Even though they look very mature at an early age, they are usually pretty 
awkward until they grow into themselves.  As far as the hoof angles, keep the 
angles close to the natural pastern angle rather than some arbitrary angle.  
Your farrier should be able to look at the pastern angle and match the hoof 
angle to that.  Besides keeping your horse collected and alert, you may want 
to have your farrier set the front shoes back slightly.  Don't have him dub 
the toe, just set the shoe back a little to help the horse breakover easier.  
Keep up the good work.

Laura