I am interested in figuring out what rear axle I have by running a part number but I do not know where to go to do this? The part number on hte side of the case is 2070741 and there is a 27 right below that. I think it may be a 8.75 inch axle because it has the front part of the case that bolts on with 10 bolts, it is not a rear cover. Also, where do you count the leafs on the rear springs, right at the axle including the helper springs or further out? I have 5 including the helper springs right at the axle. The reason I am asking all of this is because my car is an original slant 6 car (currently there is a 318 in it) and I am putting a 440 in it and want t omake sure it has a decent rearend in it. I appreciate any help.

 

Nevermind, I figured it out. I have a 8.75 rearend and 5 leafs.

 

Yes the 8 3/4 is the only one set up like what you have. Unless someone put a Ford 9' in it.