Anyone have a website that I can figure out what rear end I have in my car? This 1973 dodge dart sport originally came with a slant 6 engine, A904 transmission, and I'm not sure on the rear end. I want to know what size (8.75?) rear end, what gears it has in it, and whether or not it's a sure-grip. I checked it out earlier today while I was working on the sending unit, and I didn't see any type or stamping, casting numbers, or identification plates on it anywhere.

 

Most likely it is a 7 1/4 NO sure grip Unless it was changed when the 318 was installed. IF so all bets are off

 

"There's a chart"............

https://www.google.com/search?q=mopa...w=1252&bih=611



The 8 3/4 is the only Mopar axle which is a removable third member type.

You surely would have either a 7 1/2 or 8 1/4. The chart will tell the story

So far as rear ratio, Many guys "jump on the tag." But as old as these girls are, anyone could have changed the ratio, I prefer t o actually count them.

Jack up one rear wheel, safely block the front tires, and put the trans into neutral. Make certain the parking brake is not set. See if you can turn the wheel. If you can, turn the wheel TWO exact full turns while counting driveshaft turns. They will tell the story, 3.55 is just a tiny bit more than 3 1/2 turns, 3.23 about 3 1/4, and so on

If you can NOT turn the jacked up wheel, you have some form of sure grip / limited slip. Now you will have to jack up BOTH rear tires, and this time, turn one of them ONE full turns, while counting driveshaft turns.

 

Well crap, I have a 7.25" open rear end (non sure grip) with 2.72 gears

 

It's probably a bad idea to build a 360 and bolt it up to this rear end