18x8 fronts for a 68 charger back spacing??

[dodgey68]

hi guys
i am about to purchase 18x8 fronts and 19x10 rears, my question is (if some one can help) as my front end is not together for measurements , can some please tell me what back spacing i would need for the front rims in an 18x8 rim,
the rear is in and i have all the measurements (backspacing)
thank you for your help

[DriverzInc]

What wheels are you buying?

[dodgey68]

hi drivers inc
i have narrowed it down to either
1.intro , penita
2.bonspeed , quick silver
3.or budnik, fontana

[dodgey68]

any one help?????info