When does a tranny need rebuilding?

[HeavyFuel]

Hey, we are all for saving a couple bucks and some time/effort when we can, right?

The 727 out of my '68 worked fine before I completely disassembled the car a couple years ago.  The car did sit for years and years (indoor) before that, with very few miles put on it.  The mileage showed just about 70,000.  Now it is getting close to the time to put it all back together again. 

I am just wondering what I should really need to do the the tranny.  Just replace the input and output shaft seals? (the output is leaking badly)  Any other seals I should look at?  Obviously the filter, fluid and pan seal need the be changed.  Is there enough wear and tear on it after 70,000 miles to warrant a total freshen-up?

The 440 did get a rebuild, as well as the rear end (bearings and seals).  The car is going to be factory stock, not a fire-breather.

Any advice?

[John_Kunkel]

The only way to inspect the internal seals is to disassemble the trans and if you're going to do that you might as overhaul it.

Time can be as destructive to rubber as miles, if it's been a lot of years since the last overhaul I would do it now and get it over with.

[idahogrumpy]

I just tore apart a 727 that was working (fine?) when it was pulled from the car. (Needed some parts for another trans) This transmission was behind a small block, mileage unknown. I found that it had a broken diaphragm spring in the rear clutch pack. You will really never know until you open her up and have a looksy!   Grumpy

[HeavyFuel]

Yeah, that's kinda the way I was leaning.  Thanks, guys.

[Silver R/T]

might as well put in shift kit, upgrade it

[68chargerboy]

if its out just rebuild it know alot less head aches

[HeavyFuel]

might as well put in shift kit, upgrade it

I have considered one, but I don't want to feel "jerks" at each shift, just smooth quick shifts.  What do you suggest?