I would stay with Briggs because they are good engines and Tecumseh went out of business which means parts will be hard to find.

You do know that overhead valve engine will be stronger that flat head engine of same horse power. Overhead valve engine put out more torque. I have 2 troybilt horses both now have overhead engines 6 and 6.5 they as powerful as 8 horse flathead. 6.5 come from harbour freight was 159.00 its honda knockoff from china. Mounting same bolt threads national fine 5/16 but bolt holds pulley on was different old engine was 3/8 new was 5/16 nf thread.

Hi gator_rider2,
Could you please give me the Model# of the Harbor Freight engine you used?? (I have a HF close by) Any problems other that you already indicated above in installing it ? How about the throttle hookup?? Or just don't bother with it, and let the govenor handle it ?
I am torn between a Briggs Vanguard (=$$$$$$) and 159.00
My trusty Tecumseh just isn't worth the time+$ to rebuild.
Thank you,
Ford
RI

Model 66015 blue engine its just like 6 hp one but this one 6.5 hp called greyhound. The 6 hp one called powerhorse and has different model number. I have just installed 6.5 model 66015 on mind crank engine couple times all I've done adjust throttle so move easyier. Engine quit like honda controls same throttle choke fuel cut off all on front so may get bumper to protect all that local store order one like other one for 45.00. On other tiller I have tecumeh 6 hp over head valve engine on it throttle on front I got pull twist throttle cable put on it works good this engine sports engine for Go-carts. For time being going leave throttle on greyhound as is and see what happens.

Thanks for the info. I'm absolutely in love with:
Briggs & Stratton I/C OHV Horizontal Engine  205cc, 900 Series, 9.00 Gross Torque, 3/4in. x 2 27/64in. Shaft, Model# 122032-0536-B8
HOWEVER, the reality is, this is a 40 buck 1976 Horse I
that I have torn completely down, cleaned up 33 years of abuse (parked behind somebodys barn) and repainted. It needs tines and tires yet. The motor just isn't worth saving, but may bring a few $$ on Craig's List. The tranny seems O.K.(I changed the oil and it looked good) and no slop in the shafts). The 66015-OVGA (not available in CA) at 139.99 appears to be exactly the same as the 66014-1VGA at 159.99 which is CA certified.
Regards,
Ford
RI

SKU 66015 has maximum torque 11-N.M./2500-RPM as soon as get mini tach that where I run mind I am nut about running engine at max torque lol. For techical questions you call 1-800-444-3353. The engine meets EPA certification (2009). Other features low oil shutdown,longer engine life with bearing supported shaft, and fuel suutoff valve. The manual states this engine made in 2008 for sale in 2009.

Use the Harbor Freight engine, you'll never regret it.

Have an older troy tiller. Engine runs, runs good for a short time. Engine will sputter then dies with a puff of white smoke out of the exhaust. What could my problem be?

While the Harbor Freight 6.5 hp engine is a great value, it seriously lacks power for busting hard ground and especially breaking sod. To often the engine stalls out under load. I do garden tilling as a service full time in the summer months. This engine is a poor choice. I used it for about a month and removed it.