Is this a bad idea...
I would rebuild your current one or get a somewhat built transmission from a sponsor. It isn't that expensive and you will have peace of mind. I'm sure they would cut you a deal if you got the trans built and buy a converter.
I put a 4400 VIG in my old car at 100k miles and took it out at 116k miles with many track passes and DD the car everyday very hard. Never had one problem, the trans was in perfect working order when it went in though.



