Rearend help...

XStang302x

Founding Member
Nov 2, 2000
286
24
19
Marietta, GA
Rearend ID?

Hell...gonna take it apart this weekend and pray it doesnt rain till then heh.

Anyways, trying to figure out if I have a 8 or 9 inch rear.

68 coupe that originally came with a 289. There is no back cover plate on the rearend. It's a solid piece with a removable center from the front. I can't seem to find any guides to help decode the ID # = C70W 4025A 29. According to my shop manual from the VIN plate decoder it's a 2.79 with an 8" , who knows what PO's might have put in. I could get a socket around the bottom 2 bolts (which I was told indicates 8", was a tight fit though), maybe I have funky sockets? I have a buddy telling me it's definitly a 9" . I found a website that explained how to designate between the two, and they had a 9" with an ID number of C7AW 4025A ?? (can't remember the last two, if that even matters). Mine being only 1 letter off is what has me confused, assuming it's probably just a year indicator. Plus, I've heard that it being a solid back piece with the removable front indicates it being a 9".

Any advice from anyone with experience would GREATLY be appreciated. Looking to yank this puppy off over the weekend, hopefully go ahead and preorder any parts I need and get em on the way and have it back in early next week.

-Frank
 
Haven't taken it apart yet, but have a horrid noise on decel. So I'm assuming something is about to break. Going to try and yank it out tomorrow night and see what's up. I'm planning for the worse and just making sure fixing it will require little down time. Just not having any luck finding 8" parts on sites like summit and what not. I'm probably just being mentally retarded in that area. I see 9", 8.8" and 7.5" all over the place though.

-Frank
 
Sorry to be the post whore of the night...

I'm on a limited budget...I would like to get this fixed for under $500. I have a buddy who can help me get everything measured and assembled, so parts cost is the main worry.

With the curent mods (not much) it's pushing 300ft/lbs of torque and 190hp at the wheel. Is the 8" suitable for that amount of torque? If not I wouldnt mind spending a lil more for the 9" just to prevent future problems.

I don't know anything about rearends, though I'm learning very quickly lol.

Any opinions?

-Frank