145/65's will be the best bet on the front if its really low and the empi 5's are repro's? This was about the only tyre I could get to give proper clearance on mine. If they are original empi 5's they had a bigger offset so will tuck under the arches better which will increase your tyre options. A 185/65 or possibly a 195/65 will work ok on the back depending on what size rear axle shafts you have. Mine was a 67 and had late (long) shafts so my 185/65 x 15's just about fit but any wider would have been a struggle. Again if they are original empi's you could probably go a bit wider on the back but not much.