245/60/14 on stock rally wheels

FWIW, the 215/70's I have on my 14x5.5's feel like about the max sidewall bulge I feel comfortable with....section width is 3" wider than the rim....the rule of thumb I've always heard is max section width approx 1.4x rim width, granted that varies with aspect ratio, and that ROT is what I heard in the early 90's, back when most tires were 60-75 aspect ratio. you can get away with a bigger discrepancy with a taller aspect ratio. LT31x10.5-15's (10.5" section width, essentially a 76 aspect ratio) will fit comfortably on a 7" rim (recommended rim size 7-9"), whereas a 265/45R20 (10.5" section width) has a recommended rim width of 8.5-10"....you're probably OK going with a rim 1/2" narrower than the minimum recommended, I wouldn't go more than that.