78whtshark

I have a 1970 350/300 auto with air,

What gear should be behind it and why?

and did all 1970 come with Positraction?

I think my differential is not the original???

Any thoughts or opinions.

78whtshark

Additional info from differential cover, Number on top and upside down is 9871375 and on the pass side of cover is 10240,

anyone know what they mean?

Also, it is not a positraction now. I can rotate one tire forward and the opposite tire goes opposite way. So that is a non-limited slip differential, and not a posi.

It also a has a narrow yoke.

Gordonm

It should be a 3.08 posi traction rear. The clutch pack might be shot allowing it to act like an open rear but someone might have changed it. Try to get the numbers (letters) off the bottom of the carrier. Should be 2 or 3 letters. In 70 it should be CAL, CAV, CAW. Any of these 3 are 3.08 posi rears.

78whtshark

On the bottom of the carrier, it is stamped:

1CAV 4 13 70

Is that a 3.08 Posi or non-Posi? And is this the correct rear end for this car?

78whtshark

I beleive this is the original rear that came car, 4 13 70 would be right for a car build on May 19, 1970.

CAV is 3.08 and I believe it also a non-posi rear.

I think, I'll try to get this one rebuilt or at least keep the case.... :smash: :smash: :smash: