Oil analysis is a good thing to do in a case like this.

Is there an oil pressure guage on the van ?
What is the oil pressure with everything fully up to temp ?
I find them to be 6 psi at a hot idle ...
and even almost zero pis at a hot idle..
and as low as 22 psi at 60 mph.
At some point in a 2.1 wbxr ...
........
well, there's a great Samba post about a guy driving a 2.1 with only 12
psi at 60 mph ..
He 'enjoyed' a ventilated engine case eventually.

'smooth' doesn't mean oil clearances are where they should be.

I'd get another 2.1 and rebuilt it thoroughly  while driving this one.

On 10/20/2013 7:09 PM, JRodgers wrote:
> Why? I would keep a log on the engine - set some baselines - then run
> it. When the numbers begin to change - then I would begin considering
> alternatives.
>
> I worked as an aircraft mechanic for years. In private aircraft,
> teardowns were only done when the numbers began to get out of line.
> Otherwise - we simply ran them. Those numbers were things like
> compression numbers, oil analysis numbers, crankshaft runout, end play,
> oil pressures, oil leaks, etc. If such are good - drive the thing until
> they begin to change. THEN look at the alternatives. Enjoy your machine.
>
> John
>
> On 10/20/2013 8:58 PM, Robert Clemmer wrote:
>> I know I should open it up and do
>> the main and rod bearings but it is just soooooo smooth.
>