i want to build another gp spectea but i want to mod the wing for aleroins and spoilers i also want to make the wing tips straite and only wse the dihedrial (sp) in the center of the wing i think the plane will still fly fine but i wanted to throw it out there and see if anyone else had any ideas that would help any imput would be appreatied thanks

With ailerons yes it'll be fine. Something to consider is that the fin and rudder is sized for the polyhedral wing. It may well be a little large for the reduced dihedral. If it is the what you'll find is that once put into a turn that the model wants to tighten up unless you hold a little to a lot of outside aileron for the whole turn. This is called being spirally unstable and actually comes from too large a fin area on too long a tail moment. So keep that in mind and if it turns out to happen to you then you can make the model more neutral by cutting down the size of the rudder and fin. When it's just right the model will tend to level itself from shallow banked turns and only need a little bit of "top" aileron in steep banked turns.

If you go too far the other way then you'll find that the model wants to hang the tail low and sort of skid or side slip in the turns and you'll see more signs of adverse yaw when using the ailerons to roll into a turn.