[Mart]

There is an inch difference in the lengths of the push rods, so it ought to be obvious which is the right one for your engine. My experience is that they can benefit from fine tuning of the length. They should be made from a tubular centre with pressed in ends. It is possible to pull the ends out and insert washers to get the desired length. The washers need grinding down afterwards to get the diameter down.

Not too sure about your fan belt. Is that stuff rated for the speeds and longevity you will need?

Mart.