I bought a 7.5 posi and 4.10 gears from an ebay seller! Guy has really good ratings and sells this stuff all the time...my only question is, did i buy the limited slip differential posi? or did i just buy what i already have on my car with 4.10 gears?

all is says is "ford 7.5 posi and 4.10 gears

 

Assuming you have a 7.5 rear end, you need the posi. If you have the 8.8 rear end, you already have the posi.

And yes, posi, limited slip, tlok; they are the same thing.

Also, link the sale page. It will help us figure out what you bought

 

Okay thanks for the info and help!!! You were right about the posi!!! Thanks

 

Has anyone had problems with a posi and 4.10s on their 7.5 rear end? I have heard of the rear end getting destroyed because it is not made as sturdy as the 8.8 but since I have a six would it ever be a problem?

 

Only if you are putting a decent amount of power down with drag tires, if they are street tires they will just spin.

 

Its not the gears and posi that will break the 7.5" its when you make some power that rear end just isn't made to hold alot of power.

 

Yup. If you are making a lot of power on a 7.5, do not buy sticky tires. The second those tires stick you're going to destroy that rear end

 

Its not that fragile, but they just can't handle that kind of power. Teal Beasts Twin Turbo v6 was making almost 400rwhp on 16psi and it raced on a 7.5" with Nitto Drags for awhile before it finally exploded on the track.