Gabarger,

If your referring to the 91 Size that Seagull has out over in Europe and the Far East, I think you'll find that a 91 would be appropriate to power a plane with 70 inch wingspan. If and when we ever get a look at these new Seagull Decathlons, you'll see that the planes are wider and significantly bigger than the "40" size Decathlons, like the Phoenix/Black Horse and current Seagull offerings.