If the version you linked to is the version that you purchased(there are 2 versions of the same engine, one for the RC10GT and one for other trucks. The one you linked to is the one for other trucks.) that would put the flywheel side of the clutch bell right on the spur gear. Like you said before, your best bet is to probably return the engine and exchange it for the short crank version and buy the clutch nut, it would be cheaper that way. If your LHS doesn't have the short crank version, then just get the short crank and the clutch nut. Either way it'll work out for ya. [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGGP8&P=0]This[/link] is the engine for the GT.