Getrag to NV3500

[smokeater05]

I have a question, can I bolt a NV3500 in place of my Getrag transmission? My truck is a 1989 with a 305, 1/2 ton. I have a first generation Getrag and the front bearing has come apart. I did not these were bad transmissions. I called two transmission shops to find out what fluid it takes and one said he was sorry for me and another told me I had a junk transmission. I have done research, but have not found much information about any one swapping transmissions. Some sites say the NV3500 are not that good either. I would like to put a NV4500 in it, but I think it would take alot more work. I found a guy in town who says he can rebuilt my transmission for $500, but if I can put a better transmissin in for a little more money, I would like to do that. If any one has any done this or can lead me in the right direction, it would be much appreciated.