I have a blazer rear end, s-10 transmission and 2:73 rear gear,,,235 engine,848 heads,etc in my 52.My area is mostly flat,, I run mostly in fourth around 2,200 or a little above, this is close to 60 mph,, I shift into 5th about 65,,works fine for me,, on a real steep hill I may have to shift into fourth, depends how fast I hit it and how steep.. fourth is good crusin for me.... a 3:73 would give you more ump..... I believe when in 5th and 65 or so I am running about 1650 to 1700 rpm. a little higher if I stay in fourth,, I do it both ways,, my tires are 205/75/15......6 lug... good luck with your choice..Fred
