Do modern style thermostats work in 59 stylle heads?

[bullrunmotor]

I've gotten an old 59a motor back to life in a 35 car. Previous owner used no thermostats. Lots of condensation and sludge evident in valve galley. When running it barely ran 100 degrees according to laser temp gun. I put some 160 degree thermostats from Dennis Carpenter in the center water outlets along with new improved style water pumps. With the 160 degree thermostats I register just barely 120 degrees. Are the old bellows style thermostats that mount up in hoses near the top radiator outlets more efficient? Thanks for any suggestions