The semi local junkyard has a few 80s trucks and vans that should have the 700r4 in them (getting info is pretty much like pulling teeth) one of which will be pulled for the caprice.
I already know to stay away from v6 models and early 80s ones are weaker. Anything else I should know?
Somewhere around 89 they did away with cable drive speedo. And change filter/adjust TV cable according to the factory service manual before firing it up.
I'd also recommend a external trans cooler and adding a drain plug to the pan.
Well, if you're expecting to have it gone through anyway i wouldn't worry too much about the vintage because the problem area parts are going to get replaced anyway. I had a job rebuilding transmissions for a couple of years but i dont remember anything about early vs late 700r4 being any real issue.
In reply to Vigo:
It won't be gone thru.....although I may attempt to rebuild the original just to see if I can 
I'm missing the intended use. I might be a gm trans snob but the 700 isn't high on my list.
It's replacing the dead 700r4 that's in it now. It's not a swap.
I know the 700r4 isn't liked by some but I need overdrive and it's an easier fix for now than swapping in something
Welp, if you're not planning on going through it I would just look for the one that looks like it was most recently rebuilt. 
In reply to Vigo:
Lol, good advice.
Stampie wrote: I'm missing the intended use. I might be a gm trans snob but the 700 isn't high on my list.
Once properly set up, the 700-R4 is actually a pretty solid transmission. I've seen guys running 600+hp through them. And the gearing is pretty ridiculous, with that loooow 3.06 First and deep 0.76 Overdrive.
I always heard in the off road world that pre '86 they were weaker but that in '86 they were strengthen, don't ask me how.
Since then it seems to be more about what kind of life they have and they like clean fluid.
Have had them in 9c1 caprice and suburban without issue. I would change fluid and filter once a year and not tow in overdrive.
Good transmissions and tons of knowledge about them in the googles.
Good luck
I thought '87 was the first year of the updated ones? there was a changeover somewhere in there.
Also, no WOT upshift into 4th always seems to get the drag guys in a tizzy, if you happen to have very short gears. But like for like swap, you would already know this. EDIT: just saw it is for your caprice project, so this wouldn't be an issue.
Yea for a direct replacement I'd hit the easy button also.
Look for a wrecked car. Then you know it ran before it crashed.
Well at least ran well enough to crash. It should go without saying though to drop the pan on any trans you come across to check it out best you can
You'll need to log in to post.
