formula 3 vs renault 3.5

Hey Guys,

I realize this is a bit of a noob question, but are the cars in Formula 3 essentially the same as those used in Renault 3.5? I realize the engines are different makes, but over all, would you recommend using the Formula 3 cars is GSC 2013 in place of the Renault ones. I would like to create a season of Renault 3.5.

Is there a 3.5 mod out there if necessary?