Just had this installed in my 91 K5 Blazer... I know its not a thirdgen, but I own one and its a 700r4... Close enough.

At any rate, this kit kicks ***.. Its the heavy duty kit that Dana sells and it comes with the vette servo and I think the 465 main boost valve.

My big 5k lbs truck with 31" tires now shifts as well as, if not better then my 90 Firebird.. It doesn't bark second gear, but the 1-2 shift is nice and firm and quick. (I did not want overly harsh shifts being that the truck is a daily driver and is 4x4)

It also shifts smoothly if I stay light on the throttle, so it still behaves like stock if I'm not beating on it.

The 2-3 shift is also very impressive, very quick and moderately firm. The only thing I dont' care for is a mild clunk on the 2-3 at a moderate throttle.. At full throttle the 2-3 is perfect, and at light throttle is it smoth and not jerky. Somewhere in the middle however, it does have a bit of clunk. This could just be my high mileage trans however.

Thanks Dana for a great kit, and I would encourage anyone with a daily driver truck/car with the 700r4 to invest the $80 in this kit.

I also put a big hayden cooler in at the same time in hopes of extending the life of the trans some more.

 

ive had one of the kits on my daily driver for about 1200 miles now... it rocks!! Cruising around town its very comfortable shifting, and when i get on it, it will chirp 2nd.. and thats with 305 TBI with 2.73
already broke my tranny mount having too much fun with that one night :P
the 3-2 downshift is mean, under heavy throttle (not full) it kicks my *** and my foot comes right back off the pedal, haha.. its great though

 

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well, the internal clutches dont slip as much, which will increase the life of the clutches.. from what im told nothing else will really suffer, cept maybe your tranny mount :0

 

Since the heavy duty kit is mostly fixes for the stock problems, I think it should add quite a bit of life to the trans.

I had the usual problems,
screwed up TV cable, 2-3 shift windup, 1-2 shift late, harsh shifts, etc.

Now its smooth unless I go over half throttle.

I can't imagine running the 500 main boost valve though... the 465 or whatever size gives a pretty firm shift. If I didn't have big 31" tires and my truck didn't weigh like 5k, I bet it would chirp second gear pretty easy.