Q.Should I Dead-head Clematis Plants Or Is It Different Depending On The Plant?
I have done both and I think I recaLL one that I had that I shouln’t have. I’m afraid I don’t have all the names. One is like a Jackmanni, other 2 have smaller flowers.

Certified GKH Gardening Expert
Generally, they are deadheaded according to type. You can go by when they flower, though. They can be deadheaded just after flowering, but don't wait long after that or you risk cutting off next year's bloom buds.
Here is an article to give more information on clematis pruning groups:
https://www.gardeningknowhow.com/ornamental/vines/clematis/pruning-clematis-vines.htm