Fresh 352 on cam break in. I only had 8 qts, (11 reqd), of Type F but I figured it would be OK for break in. I had the static timing perfect and the engine started right up. I went to about 2500 RPM and held it there for about 5 mins. I shut the engine down to check fluids. As the engine slowed down, I heard a definite "clunk" . I checked fluids and found that the tranny was still at about the same level as before. I expected it to be low as the fluid was pulled down to the break suction point. I half expected problems when I started the engine back up but it ran fine the rest of the break in. At idle, i moved the selector and nothing happened. No movement, no servo noise. I put a guage on the pressure check port and had 0. I pulled tranny line, to the rad, and there was no flow. I pulled the tranny and checked the front pump. I found metal around the outer part of the drive gear. The metal part of the converter tabs that drive the pump. The pump turned freely. The driven gear showed spalling on the outer diameter. My theroy is that the pump didn't pull fluid from the start. After a while, it got hot and siezed which sheared off the converter drive tabs. The screen and seals were good so I know I didn't have an air leak at the fliter. I wasn't careful when I took the pump apart the first time. I probably got the driven gear in upside down. The manual cautions to be sure to get the gear back in the same way it came out. The pan shows no sign of metal. If the pump was dry, there was no flow at the time of failure. I will pull the regulator and look for metal. If I find none, I'm gonna put a new pump and converter on and run this old truck