Inline I think you got pretty lucky with that engine. All of the force .26s that I've dealt with at the hobby shop I worked in were terrible. Wouldn't hold a tune for anything, ran very hot, and blew glow plugs constantly. Not only from my experience but everyone else I know of has had the same problems. There was only one exception and I think the only thing that let it run correctly was running in cool weather.

The ofna comp is a good buggy but I don't trust the motor that comes in it. Also your going to need atleast a new steering servo (i don't know how the electionics are in the 7.5).