Happy Birthday gdrill!

Happy Birthday gdrill!

Happy Birthday gdrill!

Happy Birthday gdrill!

Happy Birthday gdrill.

Note to self...
Thanx to 64ValiantConv (Richard) for this info....

Another plus is that the a500(42rh) has a 1st gear ratio of 2.74/1 and 2nd gear is 1.54/1. That's a 12% gear reduction in first, making a rear axle with a 3.23 behave like a 3.61 and a 3.55 will behave like a 3.98.
Transmission A-500 904/727
Gear
First 2.74 2.45
Second 1.54 1.45
Third 1.00 1.00
Fourth 0.69 n/a
Reverse 2.21 2.21
The 42rh will bolt right up to the 273/318/360 LA small blocks.
Here's a link to a great article one of the FABO guys sent to me. It covers upgrading from a 727 to the a518, which will be identical in most aspects to the 904/a500 swap.
http://www.insuranceforhomeinspector...r/a518Swap.pdf

Note to self...
A few notes on the a500:
The a500(42rh) is the 904 based tranny with overdrive. I believe the 42rh was introduced in 1988, but I recommend getting the 1993/4/5 because the 42rh had a lot of little changes by 1993/4 and the reliability factor went up. The a500 has 2 major versions, the 42rh (1988-1995ish), and the 42re (1995ish and up). You won't use the 42re, it requires a computer (TCM) to control it. Doable, but expensive. You can tell the difference between a 42rh and 42re by the electical connector located by the shifter linkage. The 42rh will have an oblong 3 pin (one hot wire, one ground to control the OD, and one ground to control the lockup torque converter) and the 42re will have a larger round connector with 8 or 9 pins. Some 46rh (larger 727 based)trannys came with 2 pins on the early model (1988-1992?) because they didn't have a lockup converter. To my knowledge, all 42rh's had lockup converters and cam with the 3 pin connector.