transmission swap (need expert advice)

[badassbasi]

I'm currently the owner of a 1971 GMC 1500 truck. I previously had a TH 350 transmission with a 3-speed tilt steering column. I just installed a 700R4 transmission with a high stall converter. They also changed the fly wheel and the drive shaft. Here's my problem. My transmission specialist says that there is no way that I can install another column shifter to make my 700R4 transmission work due to the linkage/bracket problem that come with a 3-speed column shifter. I would prefer not to install an after market floor shifter because I would to use the space for a 3rd passenger. Could you make any suggestions on how I may resolve this problem or direct me to any websites/companies that may be of assistance. Thank you for any help that you may be able to provide.