Thread: casting numbers

Tweet

I'm just trying to find casting numbers on my TH400 and 12 bolt rear end, I've searched all over and can't find anything except on the rear end: 0140 and in another place 9969, and a GM8, but nothing that looks like a casting number. I've searched about 100 websites trying to find out where they should be, I think the tranny should be on the left just above the rear plate??? Any ideas. Also do I just compare the teeth on the rear end to get the gearing ratio??

Thanks,
Sean.

Pull the Cover on that 12-bolt count the teeth on the gears . Then divide the two#s . Also look to see if it has posi clutchs . As for the TH400 look for the ID plate on the side of the case .

if the car has a posi rear end, you can jack the rear up, if the tires both spin the same direction at the same time while off the ground its a posi, mark the tire and also a mark on the drive shaft. put in neutral and turn the tire one exact turn. count the number of times the drive shaft turns and that is your ratio. example, 3 3/4 turns is a 3.73,