Hi,
we are new on the forum but are interested in finding out if anyone knows if and where we could get a motor manual for a 1972 Barth. We are retiring and want to rebuild ours.
Any suggestions would help. Glad to know there are other Barth lovers out there. We love our 28' home on wheels!

Your engine is a standard truck engine. For servicing it, all you need is a standard service manual for that year engine. Try your local auto parts store for a Chilton's or Motors Manual that covers that engine for that year. It's doubtful you can find one specifically for 1972, but it's worth a try.

I presume you're talking about rebuilding the coach, but if you're talking about rebuilding just the engine, there are some generic instruction manuals for rebuilding engines, too.
When it comes to parts for an engine rebuild there's lots of ways to go, from your local auto parts store to some mail order houses that will sell you a complete rebuild kit, from stock to heavily modified.

Check out ebay for factory service manuals. several on there, you will need one for light truck 10-30 series.

If you rebuild the engine, I'd hope you pull the engine and replace the freeze plugs. I don't know if yours are brass or steel, but I've seen steel ones leak coolant in under ten years. There are freeze plugs between the engine and transmission, in addition to the sides and front.

You'll also need to modify the engine to deal with unleaded fuels.

You might also want to use a higher output alternator and wire harness to handle the power.

Perhaps you should consider swapping in a more recent engine. You'd get an HEI ignition as well, up through roughly 1992.

good luck!
Matt