I installed a 4l80e trans in my 72 manual trans car and I didnt have to do anything with the tunnel to get the trans in. I have it sitting in the exact same place as far as the centerline of the transmission output shaft is concerned. I wasnt able to get a stock dipstick in as the 4l80 bellhousing is just to large so I did a lokar dipstick. I used 90 degree fittings on the cooler lines and they fit ok. I did have to drill a hole down low in the tunnel for the electrical plugin on the drivers side to fit, just brought all the wiring inside at that point. Of course I had to shorten the driveshaft and modify the crossmember. So what page in the aim are the pics about modifying the tunnel for the auto cars? I need to take a look at that.