I know it is a bit off subject but my Astro Van I use for my Daily Driver and parts chaser is sluggish from 40 mph to 65, when holding a steady speed in this range it acts very sluggish when trying to speed up, I have upgraded the motor w/ cold intake & mass air sensor, exhaust, new Injection spider, complete tune up, So now the motor pulls real good from a stop but the tranny does that up and down between gears thing in the mid speed range...My question, Is there an in vehicle upgrade I can do to get the trans to perform correctly?

 

Well if the trans is in good shape I would try a little tuning first

 

A tune as in the ECM? I was thinking that a reprogram could help. The trans is in good shape w/90k on the clock and no real service done to it yet, it functions well. 2nd hits a bit hard when cold but no other probs, I was told this vintage trans can benifit from a valve body upgrade to prevent 2nd & 4th from burning out do to high line pressure, I don't know with so many horror stories out there any little glitch makes me start to worry, I just want this thing to hold up so I don't have to do a tear down in the middle of winter...Thanks for your input

 

I would try a service and good tune and see where you end up first.

 

Thanks