My dad has a rebuilt (and tuned) 390 waiting to into his 1963 Thunderbird after it gets painted. The stock transmission is a C4, and hes interested in having a higher tech and preferably a 4/5/6 speed with an overdrive. The bell housing on the C4 is removable and could potentially be bolted on a newer transmission, however some transmissions are all one piece. What are my options? Do they sell adapter kits? Whats the highest tech one that will work? I suppose we could always put an overdrive after the C4, but thats no fun is it? Besides, we need something beefier to handle the power (it should put out 450+ HP...).
