Hey guys I got a question about a dropbox. I found a good deal on a used one and i was wondering if a person has to change the gear ratios in the truck to be able to run these. I see some run 6.20s and some run 7.20s with these i got 5.13s would it make a diffrence easier on the truck etc . Thanks Tony

With a profab drop box you can use the 5.13 you have in the rears, you'll just be using the 80 90 and 100 gears vers me with 6.20 running 700, 800, 900. Now the only draw back to using a 5.13 is it puts more stress on the drive train and you'll end up breaking U joints, pinion shafts, axles.

Just get ready for the drips that come from the leaky covers from the early boxes.

What gears are you getting with the box ?

Dan

Comes with a 2.5 bull gear and a 950 and a 1500 gear set is 1200 to much or should i just regear and buy a new one and thanks Dan your always so helpful

I'd check on the cost of a new box. I know they have like 3 different cases now. But you get three sets of gears with it when you buy a new one. So you'd get the right gears for your trannie and rear gears.

If your going to use a 4 speed then you'd could get buy using the 1500 gear running in 3rd gear on the tranny = 32.8 mph @ 7800 rpm's. And the 950 gear in 3rd will get you 27.5 mph turning 8200 Rpm's.
But with 5.13's and a reverser the gears won't work for ya.




Dan

I think i will look around for a used set of 6.20's then i double checked on a new one and it is 1900.00 with one gear set i do remember when they gave you three sets of gears with them. I might just hold off till the end of pulling season cause thats when a bunch of good used parts come for sale Thanks Dan