I've got one of the old cast-iron Troy-Bilt "horse" tillers with the
6HP Craftsman/Tecumseh engines. Haven't had any problems with it in
over 20 years. Unfortunately, when tilling too close to a brick wall,
the tines hit a rock and both the tiller and I went into the bricks. I
suppose that's beside the point - other than the fact that the entire
carburetor was ripped/broken off the engine block. I really screwed
up.

Anyway, now I'm in the market to replace the engine. My questions a

1. Which brand should I replace with? Tecumseh or Briggs & Stratton or
"other"
2. Should I stick with the 6HP or go larger? (residential gardening)
3. What should I expect to pay for the engine?
4. Suggestions on sites to purchase engine.
5. Does it make sense to replace the block or buy a new engine?
6. If I have to pay a small engine mechanic for the labor to replace
the block, would it be cheaper to pay him to mount a new engine?

I'm sure that there are probably more questions, but I hate to take up
so much of your time. Thanks in advance.

Blistered Hands in Hotlanta

Do you mean that you broke the block, smashed the carburetor, or stripped the
manifold bolts, If the latter two it may pay you to repair. I prefer Briggs
myself, they are readily available and the replacement is easy.
http://www.northerntool.com/ is a good place to comparison shop although I have
foud the local TSC comparable when shipping costs are considered, Most "Horses
used a 7 hp, but judge by your 6, Could you have used more power? Another route
is a used engine but the horizotal shaft engines are not used that much anymore
and may be more difficult to find,
New a 6,5 hp Briggs Intek I/C will run $300- 400 depending on the setup. a 6.5
hp Honda about $450 and an 8 hp Tecumseh about $325