can you tell by measuring something on the outside of the diff to tell if its 7" or 7.5" as my tag is missing on my diff cover on the diff that in my kit car

I know its a 3.62 ratio and has bolt-on type driveshafts

just need to make sure i'm ordering the right size LSD diff thats all

 

measure the top of the diff, where it bolts into the bell housing.

 

as in the part on top that has a great big long bolt going threw it

 

thats it mate. what car is it??

 

iirc the 4wd diff uses 2 long bolts top & bottom whereas the 2wd just has 1 long bolt at the bottom & at the top the diff casing is tapped for short bolts.

 

diff is in a kit car

 

arh cool knew there was an easy way to tell mine has the long bolt on the top side so is a 7" which is what i thought it was

 

Another quick way to tell whether it's 7 or 7.5 inch without taking any bolts out is to look directly at the diff from behind, on the top left there is a hole machined into the casing. On a 7.5 inch diff the backplate extends to cover this and also has this hole machined in it, whereas on a 7 inch diff the backplate doesn't extend this far.