Yes, it is big enough.
I have one on my '67 3/4ton.
What are you planing on using for a master? The S-10 master has a third chamber, called a low pressure or Quick Takeup chamber. It is used with Low Drag Quick Takeup disc calipers.
I tried to use the S-10 master and booster when I put the '77 3/4 discs on my truck. I tried three masters before giving up and put the '77 master on the s-10 booster. I'm convinced that all three had a bad quick takeup valve, but didn't want to spend any more time on it.
Some masters will already have the residual valves in the outlets
