I have a line on a couple of C4 trannys as I want to install one in my '66 F100 behind a 6/300. Problem is neither is on a running vehicle. I realize it's buyer beware on these things, but what if anything can I check for to reduce the chances of getting a dud?

 

I dont think you really can. About the only thing I would do is try and find out the mileage on the trans, or maybe pull the pan on the bottom and see how much crap is in it.

The good news, unless something is really forked up inside, most of it is usually easily repaired on the old stuff.

 

First thing, if its got oil in it, is it red or brown, if brown or smells burnt look for another trans.

 

shift the gears if they dont shift then thats not good

 

I don't like to pay more than core value for any transmission I can't try out.