front wheel back spacing

[jackson]

i have a 49 ad with a g body front clip with s10 dropped spindles. i have some 15 + 5 in wheels with 3 in backspacing. i may be worrying to much about turning and the tire ( 215 /70) hitting the fender lip. i called one of the wheel builders and he said if i went with a 6 in wheel with 4 1/4 backspacing that the tire would be much more inside the fender. i dont see it . all i see is a 1/4 in gain. what do you guys think. sure i could go to a shorter tire but i like the look of the 215