My truck redlines in 5th around 96mph, but ive been in lb7's going about 120....was wondering if I could get input from you guys on what your trucks do, it came with 3.73's from the factory but I think it may have been switched by the previous owner since there was a 5th wheel in the bed before...

Are you sure that's redline and not just the speed limiter kicking in? Big difference.

If it's 96mph, I'd say that's the speed limiter. Its awful coincidental that that is also the factory speed limiter setting. IMO

I know his truck is really twisting high once you get up around 80-90. Like pushing the red, I know the speed limiter will kick in at 96 but I dont think his truck could push much beyond that with the RPMs its turning.

Stock configuration should give you about 2850 RPM at 96 MPH.
The ground speed limiter will be working then.
The engine speed limiter should be about 3200 which is about 80 MPH in forth.
They are two very different governors. Check the engine red line at a lower gear, should be 3200. Check the top ground speed on the track and the engine should never red line.
Tuners can change all that.
Fifth wheel hitch usually isn't a cause to change the gearing. They work good as stock so most people leave the gearing alone.

what kind of numbers would those be with 4.10 gears though? Thanks for that info

Yeah at 96mph im pushing right about 3150rpm