Welcome to the club Dasch. My Dad had a few trucks of that vintage. No real problems except the normal stuff you will see with any truck of that age whether it's Chevy, Ford or Dodge. One foible with all of the older small block Chevys is the rear main crank seals always leaked. They are 2 piece seals & they all leaked right up untill Chevy redesigned them & used a 1 piece seal. Not really a big problem unless they were really shot & just poured the oil out all over the clutch plate & then the clutch would end up slipping.
The only other thing I can think of is the 400 C.I. motors had siamesed cylinders on #3 & 5 & #4 & 6. This didn't allow any coolant to flow between them for cooling. This required top notch cooling system maintanance to keep them from having overheating problems. Make sure the engine temperature guage in this truck is working, & when you drive it make sure you get it completely warmed up & watch & see what the temp guage does. Take it up a couple of steep grades & see how high the guage goes. If it all seems normal then this isn't an issue with it.
Listen for abnormal noises & vibrations on your test drive. Listen for any unusual engine noise, rear end howl, wheel bearing noise, trans noise & or any vibrations that shouldn't be there. Basically look for the same problems you'd look for in a car that shouldn't be there.
The only other thing I can think of is the 400 C.I. motors had siamesed cylinders on #3 & 5 & #4 & 6. This didn't allow any coolant to flow between them for cooling. This required top notch cooling system maintanance to keep them from having overheating problems. Make sure the engine temperature guage in this truck is working, & when you drive it make sure you get it completely warmed up & watch & see what the temp guage does. Take it up a couple of steep grades & see how high the guage goes. If it all seems normal then this isn't an issue with it.
Listen for abnormal noises & vibrations on your test drive. Listen for any unusual engine noise, rear end howl, wheel bearing noise, trans noise & or any vibrations that shouldn't be there. Basically look for the same problems you'd look for in a car that shouldn't be there.
