When I bought my 68 Dart back in January of this year I was happy that it already had a 518/46RH installed. That being said, once the 318 blew a head gasket back in March, I decided to upgrade to a 340 stroker motor that will most likely push 500 hp. The transmission was shifting great in and out of OD, downshifted fine, etc. But like the motor, I have no idea on how long ago it was built or how many miles are on it. Now with the motor and transmission out, I contacted John Cope at CRT and asked for some advice on what I would need to do if I'm pushing 500 hp and may occasionally take it to the strip. I went with the 518 race rebuild kit and the TransGO TFOD-HD2 shift kit. The converter I have is fairly new (Turbo Action Street S-800 3200-3500 stall). I'm still looking for a reputable transmission shop in the SF/Oakland/NorCal area that can do this for me, as I don't have the skills for this. There was a hand fabbed crossmember which held it in place but it looked weak so I bought one from CRT. Much sturdier and I don't have to weld in mount support like the US Car Tool crossmember. I have a column shift with the OD button at the end of the shifter handle. At some point I'd like to install a floor shifter, possible a Turbo Action Cheetah, but I don't know what brackets I'll need to connect it to the top of the trans.