I have used on the street 4.56 gears with 29 tall tire and it is no big deal. I currently have 4.10s in one car and 3.91 in the other and 3.55s in the 3rd. I will stick with the gears. I like response and you will not get the that with 3.55s in a heavy car A body fine B body no. I switched to set of 3.55s in my heavy 73 and took them out same day too much of low end difference may go back to 4.30s that I ran for 4 years I never have a issue holding 3500 + heck it blows the cob webs out drive it 55 miles to track one way If you need ear plugs your exhaust is too loud