Taco wrote:
Just running the number quick it seems with a 3.08 rear end you are good to about a 7% grade to get up it in 2nd gear. So in 2nd you could run 50 mph at 4k rpm or 60 at 4800 and should have the power to do it.
Any bigger grade than 7% and you will probably be in first gear. Which would be 33 mph at 4500 rpm or about 45 pushing redline. First gear should work till about 18% grade or so.
If I were you I would try it out before changing the ratio. The rearend ratio change is about a 50 dollar option from gm so I doubt much other than a different ring and pinion comes with it. A 7% hill is a pretty good hill this is the max allowed on interstates. Most people probably will never come across an 18% grade.
I also agree it might be cheaper to just swap the whole rear axle with a truck from the junkyard than get the ring and pinion swapped. Who knows the junkyard might even take your axle as partial trade.
I did briefly consider the junkyard swap option. I like your numbers though. I too doubt that it is more than a different ring and pinion. Thanks for the input.
