4L80E trans question.
 

I bought a 1994 chevy 2500 with 6.5 turbo diesel (pics in profile) about 6 months ago and needed the trans rebuilt a couple of days later. My truck is 2wd I found a used one with less than 50,000 miles on it but was out of a 4x4 so I brought both my original trans and the 4x4 one and told the guy to make one good one. He owns a local transmission shop but he said it would be "off the records" since I was using used parts. Since it's been installed my truck won't shift into od untill I drive it for about 20min I also let it warm up for about 15min before I leave.