Identifying heavy duty vs not heavy duty brakes

[jcwren]

Last weekend I snapped up a 1970 C10 long-bed step side. It was a father-daughter restoration project that was mostly complete, but they need to sell. There is not a spec of rust on this truck, it's been repainted, new interior, lots of other new parts. It has the extra load springs, also. 250 CID, 3 on the three.

It's got an Offenhauser 3 carb intake, along with 3 TMC 1-123 carbs for it. To get it finished, I need to install the carbs, battery, inner wheel wells (came with those), front and rear bumpers (came with), bed (need to get a bed kit), and do the brakes. Which gets me to the point of the question...

Autozone and a few other places have wheel cylinders, but have both heavy duty and non-heavy duty cylinders. Is there something that identifies which the truck has? One of the front ones is leaking, and the brake hardware is a little rusty and gunky in that wheel, so I'm planning on new cylinders, shoes, and hardware for the front. The back brakes are dry, and the hardware is decent.

Any advise for a newly minted C10 owner?

Link to albumn w/ pictures