Ideally you want the offset to be around the 36 mark. Keeping it as original. However if you want a deeper dish then that will change and become smaller. The 8" wide ones i am presuming you are going to put on the rear, depending on how low you are going to go these might have bit of an issue with body movement when you go over bumps etc, as they will come up and more than likely hit the arch sill, this is easily cured by getting the lip rolled into the arch giving you a few more cm's of clearance. The fronts will probably do the same when on full lock and going round corners. But you will not know till they are put on.
