Does this truck have wheel cylinders on the front two wheels?

Nope. Those are used on drum brakes. Drum brakes were used on the front wheels through most of the 1960s, but by around 1969 to the early '70s, everyone went to disc brakes on the front. Disc brakes require more pedal effort to get the same stopping power, so most models added power brakes. Drum brakes are still used on the rear, but even there, a lot of models have gone to disc brakes on the rear because they respond better when used in optional anti-lock braking systems.

You have disc brakes on the front. They use brake calipers. Given the age of your truck, it's a pretty good bet you have drum brakes on the rear, but if disc brakes were an option, you have to look to see which you have. Calipers are plainly visible from behind the wheel, and often through holes in the wheel. They will look similar on the rear. If you have drum brakes on the rear, you can't see the wheel cylinders without removing the wheel and brake drum. To tell which type you have, you don't have to go through all that. If you don't see a caliper, you have drum brakes.