Highway RPM with the 200R4. Gotta love it!
You won't lose 1st and 2nd manual capabilities. Modifying the shifter detents is really easy once you have the shifter out of the car (as shown in my thread). The frame connectors should make it easier to make your own mount. I think I posted some measurement so you know (more or less) where the 200R4 mount ends up. The more you remove from the upper cross member the fewer times you'll have to install the GM transmission to see if it fits. I think I installed it 5 times before I cut enough off the upper cross member. I was trying to leave as much material as possible for strength/
treblig