The 904 evolved into the 500 which was later renamed the 42RH. The 727->518->46RH. 1996+ went to the RE models which are useless to you so make sure you don't get one of those.
I have read others who went to the GM 4 speed autos for better/cheaper aftermarket support and a smaller physical size to not have to cut.
One day when I get off of my ass, I want to get one of those A41 4 speed kits from Silver Sport. They are based on the GM 700R4.
Personally I prefer the driveability of a 200R4 over a 700R4 all day long, especially in a DD with a tight converter. The big 1-2 ratio drop on the 700R4 really can lug the motor down. I guess it depends on how picky you are on that sort of thing. And fitment is also usually better on the 200R4.
Free advice and worth every penny... Factory trained Slinky rewinder.........
