An available engine will certainly make a person think about a place to put it, but......

Looking at the big picture, assuming similar injectors and RPM, the 3-71 in a Super 99 has 80 belt HP, so a 2-71 might me expected to make 2/3 of that or 53 HP or so, which is not bad compared to the 44HP from the 88.

Like so many things, the devil is in the details.

For tractor use, the engine will require a variable speed governor.

Check the 2-71 dimensions from the crankshaft centerline to the bottom of the oil pan, and from the crank CL to the top of the valve cover.  The 2-71 would have to &quot;fit in the same hole&quot; as the engine from the 88.

The 2-71 was one of the first of the small displacement (71 cu in per cylinder)  engines developed in the 1930's as a smaller version of the blower scavenged 2 cycle engines used in locomotives.  That means that a lot of information on the engines will be hard to obtain.

Do you have the 88 to compare dimensions?