Sounds like you got yourself a sweet truck. An overdrive auto will definately help that old six banger sweat a little less at today's road speeds. The Chevy Astro comes with a TH 700R4-a great tranny which will be more than strong enough to live behind your six. One other thing to consider is the computer control for the trans (converter lockup?) I believe B&M, Painless Performance and others make a computer box which will allow you to properly operate one of these trannies behind an earlier carburated engine. You could also look into a TH2004R, which was a smaller auto overdrive available in big Caprices, Parisiennes, etc. No computer control on those, just normal electric operation (solenoid, I believe) Should be a little easier to hook up, no extra "black box" needed, just grab whatever wiring is in the donor car. Best of luck with you project, let us know how it works out.
Regards,
Wannabe
