Yes, you can use the /6 converter with your 904/318 combo. Torque is created in the engine, and the converter just transmits the available torque through the transmission, to the driveshaft, and then to the differential, and on to the tires. If you use the /6 converter behind the 318, it will stall and flash at a higher RPM than the stock 318 converter, but won't change the ammount of torque available from the engine. With the higher engagement RPM, the engine has a chance to rev a little higher and get more into the power band before the converter actually engages. Since HP and torque are both functions of RPM, the engine will be slightly higher in the torque curve when the converter engages, thus giving you a better off-the-line launch. Also remember that each torque converter will stall and flash differently behind different engines. Hope I didn't confuse both of us. :)
