Howdy guys, Ive been reading alot about changing the low gears in the rear end of my truck. Ive got a 235 with a Four on the floor. Im assuming the rear ratio is 4:57 to 1 and Ive read about a 3:90 for these 3/4 tons and I may have found a site. http://www.heavychevy.com/html/rearend.html They have a rear ring and pinion 3:90 for 3/4 and 1 tons but the year for them is 62-72 trucks. Ive heard that these are interchangable or at least the 67-72 years were. What is everyones suggestion or comments? Thanks guys.