I have a 74 monte with a 1972? 454 swapped in. I am wanting to put a manual behind it. The motor is mildly built and am in the process of building a 3.73 9inch posito go out back. Woundering what the best tranny would be. Looking more towards 5 or 6 speed for the overdrive and better fuel mileage. HA big block and fuel mileage aint that a joke. Thanks.