repowering an Allis Chalmer B10?

I have a 1964 Allis Chalmers B10 with a 9hp Briggs cast iron engine. I use it to cut grass in the summer and plow my 400ft gravel driveway in winter (upstate NY). It works well, but the old engine is getting tired and it seems barely powered to handle the plowing. I could rebuild the briggs, and that may give me the power back, or I was thinking of repowering it with something like a 18 HP or 20 HP briggs vtwin vanguard or Honda vtwin engine. It seems like I could fit these engines in without too much modification, but would I notice much difference in power? I know those old cast iron engines are known for their torque at lower RPM ratings.

Thanks.

 

Find a K-341 Kohler and rebuild it, it is 16hp, it has a ton of power and will last forever if taken care of. Plus its almost a direct swap. I used to have a 1965 Allis Chalmers Big Ten up until June, the 10hp Briggs was original and strong as an ox, I could push mud 14" deep with it.

Of course for the right amount of $$$ I could be convinced to sell the Kohler K-321 14hp long block (13 fin, sled puller's favorite) I have sitting at home..... If you're interested shoot me a PM.

 

Thanks for the info. Any idea what type of modifications I would have to do for the K341? is it just the mounting bolt pattern, or would I have to change the frame/sheetmetal to fit it? I am thinking the hood wouldn't fit maybe?

 

Depends on the style engine you get. Cubs will have their mounting holes drilled in from the bottom in the oil pan. JD's mount from the side into the block. Others are standard Kohler spec and should mount at an angle into the block.

IIRC, you just have to drill new holes to mount a Cub style Kohler engine (take good measurements) and find a driveshaft hub from a Simplicity/AC style Kohler to mount on it so you can hook your driveshaft up.

Wiring should not be much of a problem. www.simpletractors.com is a good resource for finding wiring diagrams for these older AC's and Simplicities.

BTW, I have a strong running Tecumseh HH-100 10hp for sale as well as the Kohler K-321 long block--Cub style mounting/block. The Tecumseh bolts through the bottom as well.