63 dart v8 swap questions

Yeah i was trying to see where i had to cut the firewall for clearence i was gonna gather the parts and throw it in on my vacation with a couple of buddies.Cutting and welding isnt an issue my brothers pretty handy with a welder. I was also just thinking about putting a 3 speed auto no need for overdrive as the car doesnt see the freeway just a 12 mile round trip to work everyday. Thanks for the input guys.