Looking to swap rear end ratio what to go with?

This is a link to a road speed calculator from roadranger.com

http://www.roadranger.com/ecm/groups/public/@pub/@eaton/@roadranger/documents/content/ct_062746.swf

 

What engine? That makes all the difference as to which ratio to use.

 

Going from 11r's to lp's will negate some of what you are after. To get down to 15 hundred @ 75mph, I would think you would have to go even higher than 3:36's(maybe 3:08's), especially with the tire size change.

 

I have 3.36's with lp24.5 tires and I'm right at 1500 rpm going 75mph. Their nice gears for going fast but they suck in the hills. Takes alot of power to turn gears this big.

 

I have '06 ISX with 3.42 rears tied to 13 spd .73 final riding on LP22.5. At 65 I am turning 1400 rpm. 1500 puts me on 70, 1600 on 75. I actually tend to like running on the slower side.... 60-62 mph and moderately heavy with rolling hills in the area I operate, so I would prefer 3.55 rears for what I do. As was stated, go onto www.roadranger.com and use their road speed calculator to play "what if" games and make an informed decision based on how your operate. I have been using it lately in spec'ing out a new ride.

In swapping, just see if the price to do it worth it. The ROI can be pretty long in some cases.

 

Mine's the same way but at least with a 13spd I can drop 1/2 a gear. I don't think I'd like them with a 10spd.

 

i have 3.25s in my 06 w9. not even turning 1400 rpms at 70. so i understand what oscar is saying about the gears sucking in the hills. i run local out of the kansas city mo area.