IF you switch from the rotory to the slide carb you will have to buy some extra linkage and construct your own linkage modification. If you want I can take some picks of the linkage I made for my Taipan when I put an STS Dragon 12R in it. But you can get the SH in a rotory carb so you don't have to do the mod. We have it in rotory or Slide.

Also the VX engine comes with either a blue or purple cooling head. We only sell the one with the purple head, because there "in my opinion" is a problem with the blue cooling heads and the factory glow plugs that are being used on the blue cooling heads, they don't seem to run as well as the ones with the purple heads.