I would recommend the following:
pull the plugs
get tdc on one of the cylinders
jack one rear wheel off the ground
turn the wheel until you hit tdc for the second time (not counting current tdc)
find out how much the wheel has turned.

you can also turn the wheel once, and see how many tdc`s you get off
the one cylinder,
and then divide by 2 for the engine revolutions.

Sudhir

On Tue, Dec 23, 2008 at 10:03 AM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> For a manual transmission, put it n gear, push the van until the tires
> make a revolution and count how many times the engine turns. This will
> give the overall gearing.
>
> Dennis