Need Help Bad

well what started out as a fluid leak out of the breather turned into a big problem.now it has no pulling power and the tranny is slipping in 1 bad, slipping in reverse bad,and loosing alot of fluid.
fluid is burned. the guy who built the tranny is trying to blame the converter and the b&m say it was not the converter. dont think it was the converter either. does anyone have any suggestions for me i dont want to get screwed.i now have 6-7000 in this project and cant afford to lose that.
I swear i have built every car in my yard not 1 problem but this truck makes up for all the rest lol.:LOL: :whacked: :confused:

Sounds to me like the lines are clogged. Or, the trannie is smoked. If the packs are burned, then the convertor may have gone with it. If you get a lot of metal in your fluid, your packs are scoured. What tranny is it? is it the t350 from the other post?

yes its the t350 from the other post it was driving fine it just leaked the reverse started shakeing and so on and so onthe coolant lines are new so is the cooler and before i put them in i blew air through the lines.