17x8's on the front..

hey all,

i'm getting ready for the front wheels and tires on my 71 dart thats converted to the large bolt circle...

i am either going to run 17x8's or 18x8's the question that i'm asking is the same one everyone asks i believe, what backspacing for the front..
for those of you running the 17x8's please fill me in..

I'm thinking 17x8 with 5 1/2 backspacing

if i go 18x8 backspacing would be the same...


or would i be better off going with a 17x7 with 4 1/2 backspacing?