what can i do to my 95 gmc 1500 to tow at highway speeds in 5th gear
It's not designed to tow anything in 5th gear. You could drop the rear end ratio way down but then you will loose fuel mileage drastically, engine RPM's will be a lot higher at cursing speed and the engine will top out a lot sooner, but the low end torque will increase, but even then 5th just won't be good for towing, the gear is just too small to carry that kind of stress.
so if i change the gears to 410 the rmps will be higher than they are now it likes towing in 4th gear but rpms are at 2500 to 3000 but can only go like 60
Right, the lower the gearing the higher the engine RPMs. Out my way if your towing something faster than 60 they just might give you a ticket. It sounds like your rig is geared for 55mph when towing. that is a safe and reasonable speed.
Looking for a Used Sierra 1500 in your area?
CarGurus has 66,147 nationwide Sierra 1500 listings starting at $1,995.
Search GMC Sierra 1500 Questions
GMC Sierra 1500 Experts