Cam degree question

Thanks guys, do they have to be flat tappet?
Princess Auto has their dial indicator and magnetic base on sale....
I hope to be near one tomorrow picking up a goodie for the build.
https://www.princessauto.com/en/0-to-1-in-dial-indicator/product/PA0002970986
https://www.princessauto.com/en/dial-indicator-magnetic-base/product/PA0002944460
For the lifter business, if you have 2 good used ones, (flat tappet) disassemble them internally and join them together, contact surface away from each other. Use as the dial contact point.
View attachment 1716021935

View attachment 1716021937

Hey Bro....I can mail you 2 lifters and an extra indicator if you want......I've got plenty:)