I have a SH .28 that I used to run in a LST, and ran it in my LSP for 2 months, it is now my back up engine though.
It runs great, lots of power with 30%, but it liked to run in the 250* range.
I was using a JP-2 for top end and a 14t clutch bell (13t is stock) and it still had killer low end in the LSP. The only reason I quit running it, was it sucked the fuel down fast and glow plugs didnt last to long compaired to my P5

P.S. Rocco's right, Mach's are made by SH
BTW, stay away from the wasp 28!