oldsbuff455

I have a 1970 W-30 , OW trans with an SF rear end was that available as an option or did it only come with a/c cars?
Where is the date code on the rear located?

orange442

It should have been an option. There should be a date code on one of the flanges of the cast iron housing but it is just a casting date for the housing, not when the rear was built or when it was installed into the car.

oldsbuff455

So if my car has a Dec. build date does a May casting date sound proper?

sicky olds

W-30s should have a TO or a T something coded rear end if not mistaken. Sounds like a regular cutlass or 442 3.23 posi rear end. will look in the book tonight and post a pic of that page for you.

Stefano

W-30 A/C with SF

sicky olds

What is the ones I am thinking about then?

orange442

You are thinking about TM 3.42 posi. and TO 3.91 posi codes that were only used on W-30 and W-31but were not the only rears you get.

sicky olds

OHHHHHH OK, my bad. thanks for the clear up on that one

Stefano

Those ratios were not supposed to be available with A/C.

3.23 SF is proper non W-27 Rear end code with A/C for a W30 in 1970.