Which Overdrive Transmission is worthy

[abodyhotrod]

what cars trucks or vans did the good overdrive come in. i found a few 80's vans with od's for $160.
are they loc up, non lock up, will a 727 coverter fit it or are they a 518 base.

 

[dgc333]

The A500 (later re designated 42RH) is based on the 904. The A518 (later re designated 46RH) is based off the 727. All A500's have lock up torque converters. A518 can have either.

 

[fishy68]

what cars trucks or vans did the good overdrive come in. i found a few 80's vans with od's for $160.
are they loc up, non lock up, will a 727 coverter fit it or are they a 518 base.

To be honest I don't think even the 518 is all that strong. I've read you shouldn't go more than 400 hp through one unless you upgrade the OD components.

I could be wrong but I think the OD section is basically the same on the a500 and a518 so you might as well go with a a500. It is smaller and would be an easier fit in an A-body. It's built on the 904 base and 904's will take 400 hp if rebuilt soundly.

727 and 518 torque converters interchange as long as you match lock-up to lock-up and non lock-up to non lock-up.

You can easily identify a lock-up trans by looking at the input shaft. The non lock up shaft is splined all the way to the end. The lock-up has about 1/2" of the front end of the input shaft turned down smooth.

 

[HawaiiDuster]

Also be prepared for the reconstuction of the floor and cross brace if you're going to put it into an abody.