What was the main reason you chose the IRC GP1's over the Shinko 244's you were looking at? Do you think I'd be good if I purchased the Shinko's, 5.10 for the Rear, 4.6 for the front. Shinko's are said to run 1-2 sizes smaller. I'd rather have the IRC's but it's more money for what appears to be a comparable tire in tread and quality.