im reading alot that changing from the 7.5 to the 8.8 will make a difference in power? is this true. if so how much am i looking at spending to do this job, my truck is a 2003 supercab 3.0 im assuming it has the 7.5 in it too. ideas and advice?
Changing the gear ratio of your present rear end would give you more power; say going from 3.73 to 4.10. The downside of the lower gearing is that it makes the engine spin faster for any given road speed, which, of course, might cause your gas mileage to go in the toilet.
Changing the whole rear end from the 7.5 to the 8.8 wouldn't result in any more power. The bigger rear end is only meant to handle the power of a larger engine.