What I have are a set of MT 29.5-9 on a 3000lb car with 4:30 gear, aprox 400 hp. Its time to replace the tires. My question is, If I went to a 28" tire, what would the 60ft change and how would it affect the mph at the stripe. Its not really alot of difference in height so I was hopeing that it would not really hurt the top end and help the car leave. The 60' on the car with the 29.5's are 1.55. What do you guys think? Thanks.