It's hard to say as the F3 cars have probably never run of the spec/compound/size of FRenault tyre and vice versa.
Be aware that a taller sidewall will stiff affect suspension geometry. You can get the ride height back again, but the outboard ends of the wishbones will be higher off the ground. That could benefit, but it's more likely to make things worse (what things are a different matter though!).
I'd say stick with the Michelin spec rubber. At least then you can vaguely compare yourself with official FRenault laptimes
