rear end ratio

Can you change the rear end ratio on the Express 3500? Or should I ask has anyone changed the rear end ratio? I want to be able to pull a good size travel trailer but to do that I would need a 4.10 ratio and we have a 3.73.

Thanks
Jo

Just an FYI, found out yes I can have the rear end gear ratio changed.
I will go from capping out towing from 7400 to 10,000. This opens up alot of travel trailer option for my Express 3500 extended van.

This conversion is costing about $1200 if anyone else was interested.

JO

I have a 1999 chevy express 1500 and is thinking of upgrading form 3:42 rear end, where should I start?