Kitchen Large Electric Appliances - Relocating range wiring

We are doing a kitchen remodel in a house built in 1965. The range will be moved to another wall. My question is: Is it ok to use the existing three wire (red,white,black) which I believe is 6 gauge and along with a junction box extend the wiring using four wire 8 gauge? Would we just not use the ground in the four wire? Is it ok to go from 6 gauge to the smaller 8 gauge?

We are doing a kitchen remodel in a house built in 1965. The range will be moved to another wall. My question is: Is it ok to use the existing three wire (red,white,black) which I believe is 6 gauge and along with a junction box extend the wiring using four wire 8 gauge? Would we just not use the ground in the four wire? Is it ok to go from 6 gauge to the smaller 8 gauge?

I think I'd just run the new 4-wire from the box, rather than say trying to run an additional ground wire. This also would lessen your chance of not making a good connection between the 6 and 8 ga. wires at the junction. And maybe your 6 ga. is aluminum?, so you would also be dealing with possibly an aluminum to copper connection? Code now is 4-wire if you run new. And 8 ga. is okay with the 40 amp breaker, and is typical for stoves.

For more opinions, you could repost on the electrical forum here.

All the wires are copper and the cicuit is 40 amp. We already have hooked up the junction box last night, but that is as far as we got. I don't really want to run all new wire, but maybe it would be for the best?