I am thinking of swapping out my factory 20 with a a set of factory 17 i currently have 275-60-20 on my 04 1500 4x2 hemi possie rear. going to change to a 245-70-17 due to the fact there free. what im worried about is doing damage to the rear or trans. Any thoughts would be helpful.

 

Don't see why it would cause any damage as that's what my truck came with from the factory. If anything it's a good size since the stock 30.5" tires are subtantially smaller than most who are running 32-33" + tires giving you a nice overall drive ratio even if you have a 3.55 rear end. This will help your tranny by taking some strain off of it, will make the truck seem more powerfull by driving the rpms up a bit and you'll probably see a mpg gain while you're at it too.

 

Shouldn't hurt anything but it will throw your speedo off.

 

Thanks for the input guys, just did the swap see how it goes.