rims and tires for my 49 fastback

hello everybody in hot rod land. Anybody out there know if I will have any problems if I install rear 15 x 7 275 /60 r15 and front 14 x 7 p225/70 r 14's the front end is stock manual steering and the rear diff is out of a 72 nova. these are radial tires. Im pretty sure everything has a 4 inch backspace.. mondoman any info would really help before I buy these wheels

 

Front should be okay - rearend you'll want to measure carefully -