Okay! That's beginning to get us down to what we need to talk about!
A 318 likely tells us it is built on a Dodge chassis and engine (stripped chassis?) with the RV then built on top.
If you get into needing parts/repair for the things that would come on a normal truck, you may need to verify that the year of the RV is the same as the chassis year!
Often there is confusion if the chassis is built in 68 but the top not added until 69! So if you go for some part like a fuel filter or brakes, there may be a difference to consider.
Finding that label may be a big help on that but also if you can find an emissions sticker out under the hood, it can tell you some good stuff if/when needed.
Click this snip for best view!
So is there anything specific that needs attention right now?
That "more experienced" RV sometimes had problems with leaks around where the top and sides meet. Those can be really important to seal before letting too much more damage be done!