66 will be a poly 318. Any LA will bolt on to it no issues. you can tell if it has 2 bolts holding down the valve covers. will also be a single pot master cylinder.

67 could be a poly if it is from canada. otherwise is first year for LA 318. Again sb should bolt up.

you will have to check balance issues if you go with a 360. As the 318 are neutral, and the 360 is not.

66 I believe still has the smaller shaft on the 727, and you won't be able to use just any aftermarket torque converter.

67 will be a 904. if it is an LA, if it is still a poly then 727