69Stanger408 82 Report post Posted September 11, 2017 I am working a restomod project. New TCI Mustang II front suspension with the supplied SBF engine mounts. I bolted my new 408W stroker to a Performance Automatic 4R70W transmission. I fabricated a trans mount and am about ready to weld it together (have cardboard templates now). My question is this, is the output shaft suppose to be centered in the tunnel or between the frame rails. I have a measurement of 16 1/8" left to right centered, to the outside frame rails. Yet when I look down through the stock shifter location (from inside the car) the trans is heavy to the right (pass side). My first attempt was off by 1.5". I had to support the trans, loosen the motor mounts, lift the engine slightly to center it, then tightened everything back. Is this correct? Quote Share this post Link to post Share on other sites
Cruzzar 22 Report post Posted September 11, 2017 As I recall mine was not exactly centered but I can't tell you by how much. What is important is that the center line of engine and transmission be perpendicular to the rear end's center line. Quote Share this post Link to post Share on other sites
latoracing 256 Report post Posted September 11, 2017 I would center the transmission between the frame rails. The shifter hole is offset towards the driver's side to accommodate the various stock transmission shifter levers. I have installed a TKO-600 in my project. Fitting the shifter up through the stock tunnel opening. I ended up cutting my new 1 piece floor to get the transmission centered in the car. Your measurements are correct. Quote Share this post Link to post Share on other sites