Priming a 340 that's been dynoed a few months ago

Do not use the starter to prime an engine, ever.

Today's parts are not designed to turn that slow for that length of time.

Seen many roller lifters killed because people thought it was a good idea to grind on the starter until oil pressure built up.

Not a good way to do it.

You ar better off to get it in the car and make it run than to do what you want. How many times does stuff sit for 2,3 or 4 months and then we jump in and fire me off and go? Happens all the time.

Make it run and go play. Unless you love to do make work stuff.