904 torque converter dont fit..?

I ran into that problem before (old engine, new trans) and just had a converter built. A local builder made one for me out of two cores for about $95 wholesale for a stock stall. That was a few years ago but I can't imagine the price it too much higher now. The problem with swapping whole transmissions between pre-'69 and post '68 is getting the neutral safety and backup lights working correctly. You can't just swap the switch as the valve body is different.